d Fm Cost User Guide

DFM Concurrent Costing® Version 2.3

Copyright © 2009 Boothroyd Dewhurst Inc. All rights reserved. This document and the software described in it are copyrighted. You You may not copy any a ny part of either the software or this document without the express written permission of Boothroyd Dewhurst, Inc. This March 2009 edition replaces the May 2006 edition. It is for use with version 2.3 of DFM Concurrent Costing.

DFM Concurrent Costing Costing User Guide

Contents Welcome Welc ome to DFM Concurrent Costing ® ..............................................5 The main window........................................................................................ window........................................................................................ 5 Responses and results results ................................................................................. 6 Machining................................................................................................... 7 The DFM Libraries Libraries .................................................................................... 8 Assembly fabrication fabrication .................................................................................. 8 Comparing analyses ................................................................................... 8

Getting an estimate ...............................................................................9 Start a new analysis.................................................................................... 9 Add secondary operations ........................................................................ 15 Making comparisons ................................................................................ 17 Reviewing results results ...................................................................................... 18

A sheet metalworking analysis ........................................................... 21 A turret turret presswork presswork analysis ...................................................................... 21 Completing part geometry data ................................................................ 23 Updating the results results ................................................................................. ................................................................................. 26 The setups for the turret pressworking pressworking analysis ....................................... 27 A compound die analysis analysis .......................................................................... 28 Reviewing results results ...................................................................................... 30

Working Work ing with the Geometry Calculator ........................................... 33 Calculating a geometry total .................................................................... 33 Transferring geometry from the Calculator ............................................. ............................................. 37

A machining machining analysis .......................................................................... 39 Begin the analysis..................................................................................... 40 Adding a machine tool setup setup .................................................................... 42 View the completed analysis ..................................................................... 44

A machining quick estimate ............................................................... 47 Using the Geometry calculator to define the part volume and machined areas................................................................................................... 49 Completing the Quick estimate................................................................. 51 Open a completed analysis file ................................................................. 51

Machining cell process........................................................................ 55 Study the machining cell results ............................................................... 57

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DFM Concurrent Costing User Guide

A deep drawing analysis ..................................................................... 59 Part description ........................................................................................ 59 Completing part geometry data................................................................ 61 Combining operations .............................................................................. 63 Comparing to another process ................................................................. 65

A fabricated assembly analysis ..........................................................69 Begin the analysis..................................................................................... 70 Viewing the completed fabrication analysis ............................................. 75

An automatic assembly analysis ........................................................77 Analysis of Individual Parts ..................................................................... 80 Results ...................................................................................................... 88 Redesign of the plate ................................................................................ 91

A printed circuit board assembly analysis ........................................ 93 Introduction .............................................................................................. 93 Analysis steps ........................................................................................... 96

Develop a user process ...................................................................... 101 Introduction ............................................................................................ 101 Define the process level formulas........................................................... 104 Define the Main response panel ............................................................. 105 Link the material library with the Forming process ..............................111

The Material Library .......................................................................113 Machining material data ........................................................................ 114 Sheet metalworking material data .......................................................... 116 Adding a new material ........................................................................... 117

The Machine Library .......................................................................119 The machine data ................................................................................... 119 Adding a new machine ........................................................................... 121 Automatic selection and the machine library ......................................... 122 Creating a machine selection profile ...................................................... 123

The Operation Library ..................................................................... 125 Add a new operation............................................................................... 125 Changing the default library .................................................................. 129

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DFM Concurrent Costing User Guide / Chapter 1

Chapter 1

Welcome to DFM Concurrent Costing ® DFM Concurrent Costing contains process and material information and calculations for quickly estimating the cost of manufacturing and finishing a part. It is designed to isolate the principal cost components, to allow you to investigate design changes to reduce costs and to compare alternative processes and materials for the part.

The main window The analysis window has both a Process Chart and a Cost results on the left side. The right side of the window changes depending on which entry in the Process Chart is highlighted.

Welcome / 5

Chapter 1 / DFM Concurrent Costing User Guide At the beginning of an analysis, or when the part entry on the Process Chart is selected, the right side of the window--the Part Description panel--contains basic part information including the envelope shape, envelope dimensions and forming direction. Picture and Notes boxes are available for each chart level to supplement your analysis. Here you see this panel as it appears with a CAD import of part geomery.

Responses and results If you have imported data from a CAD model, as above, the DFM responses and results, including average thickness, are calculated from CAD data that includes volume and projected area in addition to the envelope dimensions. If you manually enter envelope dimensions, the software calculates reasonable defaults for the remaining part geometry. In any case, if more accurate or additional volume, area and perimeter geometry inputs are needed, they can be defined in the software’s Geometry Calculator. The Calculator permits you to build up geometry (either the entire part, or selected elements) through a series of graphical prompts. (See Chapter 3 in this User Guide.) The software also supplies defaults for other responses necessary to provide an approximate estimate of the piece part and tooling costs. Most of these are user-editable. A section of the Response Panel is shown on the next page.

6/ Welcome


As you refine your inputs, you can click the Calculate button in the Cost results box to update your cost estimate. A Previous column in the Cost results pane shows the last calculated costs.

Machining Machining operations require that you first add a machine tool setup to the Process Chart. The machine tool setup will automatically include an operation for setup, loading and unloading times. Review and edit the responses for this operation as necessary. After the machine tool setup has been added, you can add machining and other operations to the setup from the Library Operations dialog. In the analysis shown below, the primary process is Machined/cut from stock. However, machining setups can be added to any process. Machining operations available will depend on material machinability data available in the Material Library. For a tutorial on performing a machining analysis, see Chapter 5 in this User Guide.

Welcome / 7

Chapter 1 / DFM Concurrent Costing User Guide

The DFM Libraries Much of the default data for your calculations comes from the three database files referred to in the software as libraries: the Material, Machine and Operation libraries. Each are user editable; for more information on using the libraries, see Chapters 13, 14 and 15 of this User Guide. In addition to machining setups and operations, you can add other secondary operations to the Process Chart at any time. These operations are stored in the Operation Library, and can be added to your analysis using the Library Operations dialog, available when you choose Insert Library Operation from the Analysis menu. In the primary process Assembly fabrication, assembly and welding operations in the Operation Library are added to the Process Chart from the Library Operations dialog.

Assembly fabrication An assembly fabrication is where two or more parts are secured using mechanical fasteners (screws, rivets, etc.) or by other securing operations (welding, adhesives, solder, etc.). An analysis can be built up on the Process Chart by inserting separate parts and operations. The assembly fabrication process allows you to directly compare the cost of an assembly with the cost of using an alternative shape generating method such as casting, forging, injection molding, etc.

Comparing analyses You can analyze your part using different processes, materials and inputs. For each new analysis, you can open a new Process Chart, or copy an existing one and alter it. The new analysis appears as a new chart tab. The new and copy selections are available from the Analysis menu. You can then compare several manufacturing options in a single file through graphs and reports. See Chapters 2, 5, 6, 7 and 8 in this User Guide for more information on makng comparisons.

8/ Welcome


Chapter 2

Getting an estimate Start a new analysis For the purposes of this tutorial we will estimate the cost per part of manufacturing 200,000 of the disk drive casings shown here:

front

back

Move the mouse pointer over a control to see a Tool Tip that briefly defines it.

The material is to be ZA-8 cast zinc alloy and the process Hot-chamber die casting . 1. Start DFM Concurrent Costing. In the Part box, type Casing in the Part name field, 001 for the Part number and 200000 for the Life volume. 2. In the Envelope shape box, click the hollow block envelope shape. Enter the Approximate envelope dimensions in inches as follows: 1.02 for the Z dimension , 0.079 for the average thickness, 5.7 for the Y dimension, and 7.24 for the X dimension.

A control can be a button, field etc. This example uses English dimensions and U.S. dollars. To change the file settings, choose Set Units from the Tools menu. You can change settings at any time; the settings choice is saved with the file. Choose the forming or die closing direction here. Not all processes require a forming direction. Dimensions correspond to X, Y and Z coordinates.

Getting an estimate / 9

Chapter 2 / DFM Concurrent Costing User Guide On charts, reveal or hide entries by clicking the or . Colors in the Process and material selection dialog mean that the selection of process and material is: green--compatible yellow--possible but may not be practical orange--no material data; compatible or possible once material data added red--incompatible, even though material data may be available

The defaults for process and material limitations, and the suitability of material to process are contained in the Material Library. See Chapter 13 of this User Guide. Depending on your monitor and screen resolution, you can maximize the window to view all of the Responses panel for the entry highlighted on the Process Chart. Or you can use the vertical scrollbar.

When you have edited a response field, the blue background means that it no longer is the default, and that the edited value is locked (it will not be replaced) during further calculations.

10 / Getting an estimate

3. Click the button Select process and material ... 4. In the Process and material selection dialog, double-click the Die casting process to show its contents. Click Hot-chamber to select the process. For the material, double-click the category Zinc alloy and click the material name ZA-8 cast zinc alloy.

5. Click the OK button to proceed with the selection and return to the first window. 6. Observe that the Process Chart now includes the material, the process, the machine setup and the process operations.

7. Default data is presented in the right panel of the window, the Responses panel. You will now want to adjust the response inputs. Each level on the Process Chart has its own Responses panel. 8. With Hot chamber die casting process selected, we can edit its responses. Change the Maximum thickness to 0.18 in. Hit the Tab key to move to the next response field.

DFM Concurrent Costing User Guide / Chapter 2 9. Supply part geometry data as follows: the number of Through holes in the part is 12, the Part volume is 5.18 cu in, the Part projected area in the forming direction is 37 sq in, and the Outer perimeter is 26.2 in. When the number of holes is greater than 0, the additional field for Perimeter of through holes is available. Enter 18.85 in. A Geometry Calculator can be used in determining these values. See Chapter 3 of this User Guide.

10. At any stage you can click the Calculate button in the Cost results pane to update the cost estimate. Let’s do this now.

Geometry data can be imported from a CAD model. To start an analysis using CAD data, choose CAD Import → Import CAD Results... from the Analysis menu. Additional information is available in On-line Help. (From the Help menu, choose Contents and Index. Look up ‘CAD Import’ in the Index.)

To unlock an edited field, click in it and choose Unlock from the Edit menu. Or right-click for edit menu choices. The Edit menu choice Unlock All will unlock all edited responses in the group box. Part weight is calculated by the software from volume and material density. Or you can enter the part weight and the volume will be calculated.

11. The default for the Surface patches response is based on the volume calculated from the initial dimensions having average com plexity. In our example, change the number of surface patches to 445.


Chapter 2 / DFM Concurrent Costing User Guide 12. Tab to the next section, Non-geometric features. For Tolerance choose most approx. 0.005 in/in ; and choose a medium finish for the Appearance field.

13. In the Die data section, we assume a Parting line with two steps; choose 2-4 steps or simple curve from the list box. 14. For holes that are parallel to the forming direction it is not necessary to provide side-pull mechanisms in the die; we can leave the number of side pulls at zero.

Uncheck Automatic Selection, change the number of cavities and click Calculate to see the effect on total cost.

The bar at the bottom of the window is the Status bar; move the mouse pointer over an object or control and look for field hints there. In addition to information on controls in the status bar at the bottom of the window, context sensitive help is available for all response fields. Press the F1 key when the field is active. ... or on the toolbar choose

For general help, choose Contents and Index from the Help menu.


15. The optimum number of cavities has been automatically set to a value of 1. This value is estimated from the size of the part, life volume and machine attributes. The automatic selection of the number of cavities considers all of these effects to result in minimization of part cost. By unchecking the Automatic Selection checkbox you can manually enter the number of cavities. For the casing, 1 cavity is optimal. Click the Calculate button.

DFM Concurrent Costing User Guide / Chapter 2 16. We have now obtained an accurate cost estimate for our part. However, we can improve on the estimate even further by looking at the machine setup and operations data. 17. Click the 130 Ton Hot Chamber Die Casting Machine entry on the Process Chart to change the Responses Panel to show setup data.

The highlighted entry on the Process Chart determines what is shown in the Responses and Cost results panels.

Machine setup data is stored in the Machine Library, and is editable. You can add new machines and new machine categories. For more information see Chapter 14 of this User Guide. To update machine library data for an analysis, choose Reload Data from the File menu. Then check the Machine Library box, and click the OK button. Your changed machine data will update your analysis. It will only update the current analysis.

18. When Automatic selection? is checked in the box above, the software selects the smallest machine by capability to perform the operation. Default machine data are shown for information. 19. Note the Rejects,% response field; the percentage of parts rejected following each operation is user editable. If the operation is within a machine setup, the reject percentage is a response for the setup. The cost of rejects is shown in the Cost results box.

When you take the Change Machine option from the Analysis menu, the Automatic selection box becomes deselected.


Chapter 2 / DFM Concurrent Costing User Guide 20. On the Process Chart, select Die casting operation. There are group boxes on the Responses panel where you can refine your estimate. Machine setup and Casting process data provide edit fields related to setup and machine operating conditions.

21. In Cycle time data, you can edit the machine cycle times for your plant conditions. To update the Die casting cycle time total after editing the cycle time fields, click the Calculate button in the Cost results pane.

22. In the last group box for the die casting operation, you can change the defaults for the tooling estimate.


DFM Concurrent Costing User Guide / Chapter 2 23. Highlight the Trimming operation on the Process Chart, and review the responses. The trimming operation in this model does not use a machine setup. Machine rates associated with trimming are available together with the other trimming operation variables in the responses for the trimming operation. 24. Choose Save as from the File menu and supply the File name casing. The file is saved automatically with the extension .dfm. Click the Save button.

The current file is not saved and remains untitled until you name it.

Add secondary operations We can add further operations to the process. We want to add a finish slot end milling operation to finish the pads. To add machining steps, you first add a machine tool setup, and then machining operations from the Operation Library. 1. With the Trimming operation still highlighted on the Process Chart, choose Insert Machine Tool Setup from the Analysis menu. 2. In the Add Machine Tool dialog, reveal the entries for the Vertical machining centers category by clicking its handle. Highlight Generic CNC machining center . Click the Add button and close the dialog. The machine tool setup and its Setup/load/unload operation is added to the Process Chart.

...or right-click in the Process Chart for menu options.

...or double-click the machine entry in the Add Machine dialog to add it to the Process Chart.

3. Highlight the Setupload/unload entry to review its responses.


Chapter 2 / DFM Concurrent Costing User Guide 4. Now you can add the finish face mill operation. From the Analysis menu, choose Insert Operation. 5. A dialog opens that lists the operations in the Operation Library. Open the Machining category by clicking its handle . In the Machining subcategory Slot/pocket end milling, highlight the Finish multiple slot end mill operation. (We choose multiple because there are 4 identical pads to finish.)

The Library Operations dialog will show only operations that are available to add to an analysis. Some factors influencing this are that machining operations can only be added to machine tool setups; or, certain materials may not have machining data for all operations. ...or double-click the operation to add it.

6. Click the Add button and close the dialog. The finish slot end milling operation is added to the Process Chart. 7. A partial set of responses is shown for the end milling operation. To complete the calculation of machining time, we must supply dimensional data. 8. The width of each pad needing machining is 0.25 in. Supply the machined surface length of 0.5 in. Enter 4 for the number of features milled and then select a surface roughness of 63µ in (63 microinches) from the Surface roughness list box. Now click the Calculate button to see the remainder of the calculated values and results for the operation. The Responses panel for the operation is shown next.



For every machining operation, an illustration of labeled dimensions to be machined is supplied in the Picture group box. If you don’t see the Picture box in the Responses, go to Tools→Window Layout and see that the checkbox for Show Picture Box is checked.

Making comparisons To investigate alternative materials, processes or design changes you can copy an analysis. 1. From the Analysis menu, choose Copy Current Analysis. A new tab appears under the chart. 2. The tab label is in edit mode; type Aluminum to distinguish it from Original in graphs and reports. Type Casing-2 in the Part name field.

With more than one analysis in a file, com parative graph and report results are available. See the next section Reviewing Results.

3. Click the Select process and material button. In the selection dialog, click Die casting, cold-chamber and, in the Aluminum alloy category, A356 Cast aluminum. Click OK .


Chapter 2 / DFM Concurrent Costing User Guide 4. The new analysis now shows the cost associated with changing the process and material. Note that the current cost results have updated and that the costs for the hot chamber zinc alloy part, before the process change, are shown in the Previous column.

To view the default material hardness, highlight the machine tool setup on the Process Chart. It is in the Basic data responses.

5. Notice the Cold chamber analysis chooses a much larger machine. This is because the optimal number of cavities under the new conditions is 2 instead of 1. All of the edited fields have been used in the new analysis, including those for the Finish multiple slot end mill operation in the machine tool setup. When the material changed, the software used the new material’s machining data to automatically update the operation time. In this case, the aluminum workpiece material in the second analysis is softer and the cutting speed reaches the spindle speed limit. 6. View the totals for each analysis by clicking the first entry on the Process Chart. Click a tab to switch between analyses.

Reviewing results To compare cost results for several processes, we now open another file that was part of your installation of DFM Concurrent Costing. The file contains five analyses of the same part using several process/material combinations. One of the analyses was carried out using significantly lower labor and machine costs to simulate relatively low-wage manufacturing conditions.


DFM Concurrent Costing User Guide / Chapter 2 1. Choose Open from the File menu. In the Windows dialog choose casting comparison.dfm from the \data\samples folder and click the Open button. 2. An image of the part, a faucet body, is included in the Picture box for the top level of the Process Chart. You may need to scroll down in the Responses panel to see it.

3. From the Graphs menu, choose Cost versus life volume. Choose all the analyses in the Select Analysis dialog by clicking, holding and dragging. Click OK .

Pictures can be added to any analysis for any chart entry. Scroll to the Picture box and click the Load button for an Open File dialog. Navigate to your image and select it to add it. Several file formats are accepted, including .jpg (uses less hard drive space) and .bmp. You can compare up to five analyses in a graph. Zoom in:

Bar cost breakdown:

Stacked bar cost breakdown:

Table cost breakdown:

Cost reducion guide:

4. For each analysis a curve of the total part cost versus the life volume is displayed. Each line is color coded and on the right panel, the costs for a life volume of 100,000 are displayed.

To view graph results for a different analysis, on the toolbar choose:

5. Type 200000 in the life volume field and observe the change in totals and the repositioning of the slider in the graph. 6. Click the Zoom in button on the toolbar. Click on the graph and, holding the left-click button, drag. You can outline around where the lines intersect to see in closer detail.


Chapter 2 / DFM Concurrent Costing User Guide Note that the status bar displays the cost and percent of the total cost represented by the bar or bar section as you move the mouse pointer.

To view reports before printing, click the Print preview toolbar button:

7. Click the toolbar button for Bar Cost Breakdown and observe the cost breakdown for the five analyses. 8. Click the toolbar button for Stacked Bar Cost Breakdown to see the total cost for each analysis. 9. Click the toolbar button for the Table Cost Breakdown, which shows the cost results for each analysis. Change the life volume field to the original value of 100000. 10. Click the toolbar button Cost Reduction Guide. Choose the investment cast analysis in the dialog. Click OK . 11. The chart shows the contribution of selected cost drivers to the total cost of the part, which is included in the text summary above the graph. You can print it as the Cost Reduction Report . 12. Close the Graph window; you can close the file but leave DFM Concurrent Costing open by choosing New from the File menu.



Chapter 3

A sheet metalworking analysis In this chapter, we follow the steps used to create a turret press and a compound die analysis for the part modeled in the sample file sheet metal stamped part.dfm included with your installation ( \data\sam ples) of DFM Concurrent Costing.

A turret presswork analysis

From the File menu, choose New; or on the toolbar click:

1. Start a new analysis in DFM Concurrent Costing. 2. In the Part Description panel, enter end plate for the Part name, press the tab key twice to move to the Life volume field. Enter 25000. 3. For Envelope shape, choose the stepped block. Enter the dimensions as shown below. Note that the forming direction is Z.

A sheet metalworking analysis / 21

Chapter 3 / DFM Concurrent Costing User Guide 4. With this data entered, click the Select process and material button. The defaults for process and material limitations, and the suitability of process to material are contained in the Material Library.

5. For the process choose the Sheet metal stamping category and the Turret press process. For material, choose Low carbon steel, cold rolled, commercial quality from the Carbon steel category. The process and material selection entries both show green indicators, meaning there are no practical limitations. Click the OK button to calculate some preliminary results. 6. The focus on the Process Chart is now Turret pressworking and the Responses Panel on the right has default data from the Part Description panel and the Machine and Material libraries. 7. We are now going to replace some of the default information used in the original estimate to improve the accuracy of the results. In the Basic data section, change the Batch size to 2500.

The software has selected the smallest turret press capable of processing the specified sheet size and thickness from the machine library. You can select a different machine and/or sheet size. Rightclick the turret press on the Process Chart and choose Change machine from the menu.

Response data after the process and material selection provides a quick initial estimate that may be reasonable, but not entirely accurate.

8. Notice that an optimal sheet size has been selected, with the num ber of parts per sheet calculated from the sheet size. The software has also estimated the unfolded length and width of the part. 9. We can more accurately define the flattened dimensions. In the Part basic data section, change Unfolded length to 4.47; and enter 3.6 for Unfolded width.

10. Click the Calculate button, to apply these changes to the Cost results box. 11. Scroll down (if necessary) to the next data box, Additional setups, where the software has specified an additional machine setup, a press brake, to form the bend. We accept this, and move to the next data box, Turret pressworking blank data.

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Completing part geometry data 1. To specify the part geometry data, open the Geometry Calculator (View menu Geometry Calculator.) In the Geometry Calculator window, notice that there are four tabs under the Geometry Chart. →

These correspond to the appropriate geometry response section on the main window. 2. On the right panel for each tab, there are instructions for adding geometry elements on the tab. Also notice the toolbar(s) on the left side of the window; the buttons on the toolbars are used in adding elements to the Geometry Chart. To see the toolbars associated with each tab in this analysis, switch between the tabs. 3. First we will define the area of the blank. On the Blank area tab, click the rectangle button on the area toolbar to add the rectangular area to the Geometry Chart. Press the Enter key to accept the name. On the right panel, enter its dimensions, 2.25 and 4.47. Tab to move from field to field. Click the rectangle button again, and enter the dimensions 1.35 and 4.47. The Chart now looks like this:

4. If you click the Blank area entry at the top of the Geometry Chart, you see the total area of 16.092. 5. Click the Blank perimeter tab under the Geometry Chart. 6. The toolbar changes to a set of buttons for inputting lines, arcs and profiles. For this rectangular part, click the toolbar button Linelength specified 3 times, to add 3 line segments, to the Geometry Chart.


Chapter 3 / DFM Concurrent Costing User Guide Enter the line length and repeat count for each entry as follows:

This perimeter toolbar allows you to break down the blank’s perimeter into individual segments. Each perimeter segment that exists on the blank should be entered so the software can accurately determine the number of turret press hits required to create the blank perimeter.

In the initial cost estimate the software provided after selection of the process and material, an estimated number of holes, and hits needed to produce them, was provided based on part definitions. These estimates will be replaced with accurate data from the geometry being calculated here.

Line length

Repeat

4.47

2

2.25

2

1.35

2

7. Click the Blank perimeter top level entry on the Geometry Chart to view the chart and totals beneath it.

8. Move to the Features tab. To determine the area and perimeter of punched holes, add 3 entries for circular holes from the Holes toolbar. The diameter and repeat count for each are as follows:


Diameter of hole

Repeat

.24

2

.6

4

.16

2

DFM Concurrent Costing User Guide / Chapter 3 9. Click the top entry on the Features chart to see the totals for holes punched, including the number of holes, the area of holes and the number of punches required. In this example, all the holes are regular and can be created with standard punches. No custom punches are necessary.

The Holes toolbar for the Features tab is at the far left. The middle toolbars have form features and perimeter elements buttons. The right toolbars are the single bend button; and the area buttons which are used to define an irregular hole. To define an irregular hole, first click its button from the holes toolbar to add it to the Chart. Then add from the Area and Perimeter Elements toolbars as required.

10. To complete the Geometry Calculator entries, click the Press brake 1 tab. Add a bend by clicking the bend button (the only button available) and entering the length of 4.47. 11. The geometry specifications are now complete for this part. We can transfer the geometry as we close the window ( Geometry menu Transfer and Close.) →



Updating the results 1. On the Responses Panel, when the Turret pressworking is highlighted on the Process Chart, all the data from the Calculator has been transferred, including those fields for which we did not calculate a value. Here is the transferred data from the Blank area geometry tab. Geometry data can also be transferred selectively selectively.. On the Responses Panel, right-click in a geometry field for a menu. Choose Transfer Geometry Data to transfer data to that field. Or choose Transfer Section Geometry Data to transfer geometry data to that section.

2. Similarly, the data we calculated on the Features tab has been copied to the Turret pressworking features data box. The background for all responses in these data boxes is blue, indicating that previous data has been edited, and and that the values currently here will not be replaced during a calculation unless the response field is unlocked. (With the cursor in a field, choose Unlock or Unlock section from the Edit menu.)

Once geometry has been defined, the material cost per part is updated updated based on volume. The software calculates volume internally, and adjusts the material cost result for the scrap rate and scrap value.

3. In the Press brake 1 data box, the geometry defined on the Press brake 1 tab has been transferred. 4. Click the Calculate button to update the Cost per part results; the turret press portion of the analysis is complete.

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DFM Concurrent Costing User User Guide / Chapter 3 5. Change the name on the tab from Original to Turret . Double-click in the tab name to put it into edit mode, type and press the Enter key. 6. Save your analysis ( File menu Save.) Name the file by typing endplate new into the File name field in the Save dialog. Click the Save button. →

The setups for the turret pressworking analysis The software has automatically added two machine setups for completing the cost analysis. Each of these setups and the operations completed on them has response data which can be edited. No further changes are necessary for this part, but we will review one of the setups.

Each process in DFM Concurrent Costing calculates material cost in a slightly different way, depending on the nature of the process. In general, the material cost per part is based on the weight of the finished part, either directly entered, or derived from the finished volume and density. This figure is then adjusted for scrap rate and value.

1. Click the Trumpf Trumatic TC2010R Turret Press on the Process Chart.

2. In the responses on the right panel you can edit the data for the turret press. Notice that the first response, Machine selection, is a checkbox for Automatic Automatic selection? of the machine.

This means that the software automatically selects an appropriately sized machine from the Machine Library Library.. The turret press chosen for this analysis was automatically selected by the software because it was the least expensive turret press in the Machine Library that could process the 0.075 inch thick, 48 inch long by 36 inch wide sheet used to make the endplates. 3. The setup rates and times for this machine are set in the Load and entry,, shown on the next unload sheet operation under the setup entry page.

A sheet sheet metalworking analysis / 27


Now we are going to change the sheet metal process type and do a cost comparison of the two processes.

A compound die analysis 1. Make a copy of the turret press analysis ( Analysis menu Current Analysis.)

Copy

→

2. A copy is created at the second tab under the Process Chart. The tab name is highlighted in edit mode; type Compound and press the Enter key. 3. With Low carbon steel, cold rolled, rolled, commercial commercial quality sheet metal part highlighted on the Process Chart, click the Select process and material button. 4. In the selection window, window, in the Sheet metal stamping category , choose Compound die for the process. For the material, again choose the Carbon steel category, Low carbon steel, cold rolled, rolled, commercial quality. The warning message Switching processes will delete... appears when you change material and/ or process. Data appro priate to the new analysis will be kept.

5. Click the OK button in the selection window. At the confirm dialog, click the Yes button to complete the change of process and return to the main window. The Process Chart now appears:

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DFM Concurrent Costing User Guide / Chapter 3 6. The Compound die stamping process is highlighted on the Process Chart. There are three setups now: the separate bend forming setup is still needed, and there is now an additional power shearing setup for cutting the sheet into strips for processing. 7. In the Part basic data box, the unfolded length and width of the part have been copied from the turret analysis. The additional response, Processing direction, lets you indicate the part unfolded dimension that will lie along the strip length. The default Processing direction gives the optimal part layout, which will result in maximum material utilization. 8. Scroll down if necessary to view the Additional setups box. The values from the turret analysis have been copied. We are going to make a change here, because of the different capabilities with a stamping setup. Change the Press brake value to 0 and the Die bend forming value to 1. Press the Tab key and click the Calculate button. The software has replaced the press brake setup with a 32 Ton Minster stamping press for the die bend forming operation.

9. In the next data box, Compound die operation data, the geometry values have been copied from the turret analysis.


Chapter 3 / DFM Concurrent Costing User Guide 10. With the Compound die stamping process still highlighted on the Process Chart, we need to edit the Form bends 1 data box. Edit the Number of bends to 1; and the Length of bend lines to 4.47. When we switched to a die bend forming operation from a press brake, the software did not assume the bend is the same. As with the other geometry features, it is not required that you use the Geometry Calculator to enter the dimension (or total dimensions) for the bends.

The rejects cost result shows zero. But a cost per part has been calculated and it is smaller than 2 decimal places. To change the Cost results decimal display, choose Window Layout from the Tools menu. Change the No. of decimals field.

You can add an existing DFM analysis to a file by selecting its file name in a selection dialog. ( Analysis menu-> Import DFM Results.)

11. Click the Calculate button to update the Cost results. Highlight the top entry on the Process Chart to see the total Cost results:

Reviewing results When you have two or more analyses in a file, you can compare the results. One way is the graph Cost versus Life volume. 1. With the endplate new.dfm file still open, choose Cost versus Life volume from the Graphs menu. 2. In the Select Analyses dialog, highlight both analyses by click and drag.


DFM Concurrent Costing User Guide / Chapter 3 3. Click the OK button to open the Graph window. You can see at a glance that the break-even point between the two processes, indicated by the intersection of the two curves, is about 140,000 parts. This means if the life volume is less than 140,000 parts, a turret press process using general-purpose tooling would be most cost effective. A compound die process, with its greater up-front tooling investment, becomes more economical as the life volume increases over 140,000 parts.

4. To print the graph as a report, choose Print Preview from the Graphs menu. The Graph report includes a breakdown table of comparative costs. 5. Before printing, review the page setup options to provide your report with customizable headings and other print features (Print Preview File menu Page setup.) →

... or on the toolbar choose

See the Help topic ‘Page setup dialog’ in the Index for details on using this feature.



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Chapter 4

Working with the Geometry Calculator To estimate the cost of manufacturing, it is necessary to have an accurate estimate of part geometry. Depending on the process, the geometry data needed can include: • volume of finished part or cores • projected area of part or cores • outer perimeter • area and perimeter of blanks • area of through holes • perimeter of through holes • geometry of levels in powder metal processing • form feature dimensions, length of bends, turret presswork punching information For each process, the appropriate fields for the required data are included in the responses. The values can be entered directly in the analysis. However, if all or some of these are not known, you can use the Geometry Calculator to estimate them, and then transfer the results to the correct responses fields.

Calculating a geometry total 1. Open the file geometry calculator.dfm included with the software (\data\samples). The part is the casing analyzed in Chapter 2, before any editing of the responses.

From the File menu, choose Open. Or on the toolbar click

2. Click the entry for the die casting process on the Process Chart to show its responses.

3. The Part geometry responses have been estimated by the software from the Approximate envelope dimensions on the first window.

Working with the Geometry Calculator / 33

Chapter 4 / DFM Concurrent Costing User Guide ...or on the toolbar choose

The number and names of tabs on the Geometry chart is specific to the process.

4. Choose Geometry Calculator from the View menu to open the Calculator. Note that the results below the Geometry chart are zero. The chart contains the top-level entry Part ; the tab for the chart is also Part. 5. The Instructions tab on the right side of the window contains instructions specific to die casting. 6. Click the block on the solid shape toolbar on the left side of the window.

In several processes, such as casting, powder metallurgy, and sheet metalworking, additional tabs will be displayed.

7. The entry Block is added to the Geometry Calculator chart. With the Block entry in edit mode, type Basic box shape to rename the entry and press the Enter key. Click the box shape in the Shape section on the Dimension tab page.

You can edit any chart entry name by clicking it to select it. Click again and begin typing when the entry is in edit mode. Press the Enter or Tab key to accept the edit.

8. Enter the dimensions for the casing box as follows: 0.079 wall thickness; 1.02 height; 5.7 width; and 7.24 length. Press the Tab key to see the volume 5.161 cubic inches in the results volume field under the Geometry Chart.

It may be useful to name and/or number the geometry elements for easier review later. Move entries on the Geometry chart by cut and paste or drag and drop techniques.

34 / Working with the Geometry Calculator

DFM Concurrent Costing User Guide / Chapter 4 9. Since the direction Z is the direction of forming or die closing, click the Z button in the Projected area section. Note that the projected area of 41.268 in2 appears in the Results. Also note the Perimeter tab (next to the Dimensions tab on the right panel) where you specify the perimeter in a plane perpendicular to die closing.

The Area toolbar buttons are used when it is necessary to calculate area separately from volume.

10. Click the Perimeter tab. To include the sides of the rectangle seen in the Z direction as part of the perimeter, single-click the button next to each dimension field. A plus sign appears, indicating that the dimension will be added to the perimeter; the length of each side is displayed. Try clicking one of the buttons again. The plus sign changes to minus (the length is now subtracted from the total.) To recover, click twice, once to make the field blank, which excludes it from the total, and once more to return it to a positive length. If you need to edit a dimension (for instance if only a part of it contributes to the perimeter), click the button until it is blank. The field is now editable; enter the applicable length in the field and it is included in the perimeter total.

11. The casing has four small bosses on its inner surface. Click the cylinder button on the solid shape toolbar. 12. Name the entry Bosses and press the Enter key. Enter 0.4 in. for the boss height and 0.25 in. for diameter. The bosses do not contribute to the projected area, therefore, you do not need to click on any of the buttons in the Projected area section. 13. In the results pane, change the repeat count to 4 and press the Tab key to complete the entry for the bosses.

The results for a geometry element show only the repeat count of 1. The top level total calculates all repeat counts.


Chapter 4 / DFM Concurrent Costing User Guide You must add any through holes in the direction of die closing separately from other holes because you need to select the Z direction projected area for these. This will ensure a correct estimate of the part projected area and the required machine clamp force needed for this die casting analysis.

14. Several holes in the base of the casing can be seen in the direction of die closing. To specify these holes we must use the Through Click hole button at the bottom of the solid shapes toolbar. this now and edit the name of the entry to Large cylindrical hole. 15. With this entry highlighted, click the cylinder button on the s olid shapes toolbar to add an element to the through hole. See that the negative cylinder shape is selected.

16. Enter the dimensions of the hole as a depth of 0.079 in. and a diameter of 1.5 in. Specify the Z direction for the projected area in the direction of forming. 17. Click the Perimeter tab and click the button once to show the positive circumference of the hole.

18. In the results beneath the Geometry chart, note that the volume and area of the hole is negative and the perimter is positive.

19. Click the first entry on the Geometry chart, Part , to view the totals beneath the chart. Note that the perimeter of the through holes has been displayed separately from the outer perimeter of the part. A view of this is on the next page.



20. While this is not the complete part geometry, we can now go to the next section of this chapter, Transferring Geometry.

Transferring geometry from the Calculator Once you have completed calculating the detailed geometry of the part, you can transfer the data to your analysis. There are three ways to accomplish this: • choose Transfer and Close from the Geometry menu in the Geometry Calculator. This will transfer all geometry totals for all tabs to the corresponding fields on the Responses panel. • close the Geometry Calculator without transferring and then choose Transfer Section Geometry Data from the Edit menu (or right-click in a Part geometry field to select this command.) Geometry Calculator results for the section are transferred. • close the Geometry Calculator without transferring and then transfer geometry for a selected response. This will transfer the single geometry total (i.e. volume, area, etc.) to the specific response field. 1. Choose Transfer and Close from the Geometry menu. 2. The Geometry Calculator is closed and all of the data is transferred to the Responses panel.

If you are importing data from a CAD model, you may still need to calculate some part geometry data in the Calculator. The selective single field transfer option is then useful. Even if a field has been edited (has blue background) you can transfer geometry and overwrite the value. It is not necessary to unlock it. Do not use the option Transfer and Close from the Geometry menu, unless you have specified the geometry for each tab, to avoid transferring zeros to fields where you may have data already entered.


Chapter 4 / DFM Concurrent Costing User Guide 3. Click the Calculate button to update the part weight response.

4. From the File menu, choose Revert to Saved to leave the file in the original condition in case you wish to repeat the tutorial in this chapter.



Chapter 5

A machining analysis Machining is the process of removing material from a workpiece. This is a common process for creating parts, especially metal parts. Machine tool setups provide a means of holding a cutting tool or abrasive wheel, holding the workpiece, and providing for relative motion between the two in order to produce the desired surface. In DFM Concurrent Costing, you can model rough and finish machining operations on parts formed by another process. You can also model the machining cost of producing the specified part from a stock material shape. The following tutorial shows such an example. This tutorial models a hollow cylinder base, which is cut from bar stock, and then various machining operations are performed on a turning center. The complete analysis is contained in the sample file machined or cast part.dfm included with your installation of DFM Concurrent Costing ( \data\samples), and includes a picture of the cylinder base. A drawing with dimensions appears below. In the completed analysis, we compare cost results where the same part is:

• machined on separate machines for milling, drilling etc. • machined on a single turning center • finish machining on a sand cast workpiece

A machining analysis / 39


Begin the analysis 1. In a new analysis, complete the part description as shown here:

For this analysis, the Approximate envelope dimensions are those for the completed part. The stock form from which the part is to be machined is the form before machining takes place.

2. Accept the default forming direction of Z because this is the direction the bar stock would have been produced. 3. Highlight the Original name on the tab beneath the Process Chart by double-clicking it. Type Stock and press the Enter key. 4. To select the process and material, click that button. 5. On the Process and Material selection window, open Machining or cut from stock , choose Machined/cut from stock for the process. For the material, open the Stainless steel category and choose Generic stainless steel. 6. Click the OK button to return to the main window with the responses for the stock process on the right panel. 7. Note that the stock material form is defaulted to round tube, because of the envelope shape selection. However, select Round bar or rod for the stock material form. Click the Calculate button in the Cost results box.

40 / A machining analysis


8. We leave the cutoff method as is. The material cost and scrap value are supplied from the Material Library and can be edited for this analysis. 9. Review the Volume and Weight fields in the Part geometry section. The Part volume displayed at this point is set equal to the work piece volume. As material is removed by machining, this value will change accordingly if you have not entered the final part volume. In this case, we know the finished volume of the cylinder base; change the volume to 20.74, and click Calculate to update the Weight field.

10. Review the responses for the Workpiece. Here, the fields affecting workpiece cost and volume before any machining operations have been done are recorded.

11. Click the Abrasive cutoff entry on the Process Chart. The responses for this step are on the right panel. For this analysis we are not ad justing these defaults, which include the labor rate and setup time for the cutoff operation.

If you do not supply a Volume or Weight here, the software calculates the material removed during machining operations and continuously subtracts it from the original volume. The part volume produced in this way will be substantially correct. In either case, loading and unloading times use updated weight totals. There is no adjustment to the volume for material removed during finish machining.

The default values for the workpiece are taken from the Approximate envelope dimensions you supplied before selecting the process and material.



Adding a machine tool setup Now we move the workpiece to the turning center. ...or on the toolbar click

1. First we add a machine tool setup ( Analysis menu Insert Machine Tool Setup.) In the dialog, open the category Lathes, if necessary. Click the Haas SL-10 CNC lathe.

...or double-click the machine to add it.

2. Click the Add button to add the CNC lathe to the Process Chart.

→

3. Close the Add Machine Tool dialog and view the responses for the lathe. 4. Note that we could change the batch size for this setup as well as the material hardness. For this tutorial we will accept the defaults. 5. Also in the Basic data group box is Rejects, %. This is the percent rejects following operations in the setup. The cost of rejected parts is shown in the Cost results box, under the Process Chart. 6. If necessary, scroll down to the Result box in the Responses Panel where total cycle time and total setup time are displayed for the setup. These will change as machining operations are added. 7. Click the Setup/load/unload entry that was automatically added to the Process Chart with the machine to review its responses in the right panel. Here the rates and times for setting up the machine tool, and any fixture and programming costs can be supplied. 8. In the Work handling box, choose 3-jaw chuck from the Workholding device dropdown list. Change the Number of reversals to 1 because the part must be machined from both ends.

Note that a figure for additional down-time is displayed. For the machine tool setup we have chosen, two machines are tended by one operator and down-time on the machines results if the operator can’t get to one of the machine in time to load a new workpiece. This additional downtime will reduce as we add machining operations to the setup. For the present example, additional down-time will be eliminated when all the operations have been added.

9. Click the Calculate button to update the Cost per part results.


DFM Concurrent Costing User Guide / Chapter 5 10. Now we can add machining operations. Choose Insert Operation from the Analysis menu to open the Library Operations dialog. 11. In the Machining category, open the Drilling subcategory. Highlight the Drill single hole operation, and click the Add button to add it to the Process Chart. It is added beneath the Setup/load/unload operation. 12. The Responses Panel includes a picture of the drilling operation with dimensions labeled, to simplify assigning the correct dimension. The software does not calculate a result until you enter the dimensions and click Calculate.

13. Enter 1.5 inches for the diameter ( dh) and 6 inches for the length (lh) of the hole to be drilled. Change the tool material selection to Carbide. See that the box remains checked to include the tool replacement cost for the drilling operation. 14. Now click the Calculate button. Here are the responses after dimensions have been supplied:

... or on the toolbar click

...or double-click the operation name to add it.

You can leave the Library Operations dialog open, and move it out of your way by grabbing its title bar with the mouse, and dragging. Or you can “dock” the dialog by grabbing the title bar and dragging it under the toolbar on the main window to the left of the Process Chart. To float it, click and hold its title bar while moving it off the toolbar. This machining model estimates tool wear from data supplied in the Material Library. For information on the tool material data that is stored in the Material Library, see the Material Library chapter of this User Guide.

Because machining operations are added from the Operation Library, there are no Help topics directly linked to fields. But hints are available in the hint bar when you pass the cursor over the response.


Chapter 5 / DFM Concurrent Costing User Guide Special tooling cost is any cost of special fixtures that are not included elsewhere. Operation time includes the time to position and change the tool if necessary. Defaults for these times are available in the responses for the Machine tool data.

15. The Cost results are as below in the Current column. If this is the first time you have clicked the Calculate button to update the Results, your Previous column will be zeros. Each time you click Calculate, the columns lets you compare the change to results from any edits you have made.

We would continue adding machining operations until all the surfaces of the part have been machined and the holes in the flange have been drilled and tapped.

View the completed analysis 1. To view the completed analysis, choose Open from the File menu. In the Open dialog, locate the machined or cast part.dfm file (installed in \data\samples.) There is no need to save the analysis we have started for this tutorial. 2. In machined or cast part.dfm there are three analyses. The first, Stock sep. setups, is where separate machine setups are used for end milling the slots and for drilling and tapping the flange holes. The second analysis, Stock/mill/turn, corresponds to the analysis you started in the tutorial and uses one setup. The third analysis, Casting , is where the part is cast and then finish machined. 3. To compare the three analyses, select Cost vs. Life Volume from the Graphs menu, and highlight all three analyses in the Select Analysis dialog.


DFM Concurrent Costing User Guide / Chapter 5 4. When the Graph window opens, click the Zoom In toolbar button (View menu Zoom in.) Expand the area of the intersection of the curves by dragging the zoom cursor over that section of the graph. →

Note that for this part it is always less expensive to machine from stock on a single setup rather than multiple setups. Also note that if less than 50 parts are manufactured, machining from stock on a single setup is the most cost effective manufacturing approach. If more than 50 parts are manufactured, it is less expensive to first sand cast the part and then finish machine critical surfaces.






Chapter 6

A machining quick estimate With the DFM Concurrent Costing software, two types of machined/ cut from stock analyses are possible; namely a Full analysis and a Quick estimate. If accuracy of results is of the utmost importance or a detailed breakdown of the machining cost is required, a Full analysis is recommended. However, a machining Quick estimate is helpful when detailed knowledge of machining operations and machine tools is not available. A Quick estimate is also useful when a rough estimate of part cost is needed very quickly and with less effort than that required for a Full analysis. In this tutorial, we will generate a machining Quick estimate for the machined part shown below. We will also compare the Quick estimate with a Full analysis to estimate the difference in the cost results.

A machining Quick estimate and a machining Full analysis for this part have also been completed and stored in the cylinder.dfm sample file installed with the software.

A machining quick estimate / 47

Chapter 6 / DFM Concurrent Costing User Guide 1. Start a new analysis in DFM Concurrent Costing and complete the part description as shown below. For a machined part, the forming direction chosen should be the direction normal to the cutoff plane. The workpiece for this part will be cut off across its diameter so the forming direction selected by default, Z, is correct.

2. Click the Original tab beneath the Process chart and enter Quick estimate. Press enter to rename the analysis tab. 3. Click the Select process and material button. 4. On the Process and material selection dialog, open the Machining or cut from stock category and click the Machined/cut from stock process. Choose the Generic stainless steel material in the Stainless steel category. Click the OK button to accept the selections and return to the main window. 5. The Stock process entry is now highlighted on the Process chart. In the Response Panel on the right, click Quick estimate in the Analysis type group box. Click the Calculate button to generate a default cost estimate for the machined part. This default cost estimate will now be refined so that a more accurate Quick estimate is generated. 6. Select Round bar or rod from the Stock material form dropdown. 7. Click the Machining operations entry on the Process chart. In the Part shape classification group box, click Primary rotational and secondary (features). Click the Calculate button to update the default values and results for the machining operations.

48 / A machining quick estimate

DFM Concurrent Costing User Guide / Chapter 6 8. This part must be machined from both ends and as a result will be reversed once during machining. For this reason, enter 2 into the Number of clampings input. 9. Rough turning is carried out on the outside diameter of the small flange and the outside diameter of the center section. A large nonsecondary hole is drilled through the center. For these features, enter 3 into the Rough turned features input. 10. Enter 4 into the Rough milled features input to account for the four rough milled slots in the part’s center section.

The central hole is too large in diameter to be considered a secondary hole and is included in the count of rough turned features.

11. Finish turning is carried out on the outside and inside faces of the large flange, the outside face of the small flange, and the central hole. For these features enter 4 into the Finish machined turned features input. 12. Enter 4 for both the Drilled secondary holes and the Threaded features inputs to account for the four secondary holes that are drilled into the large flange and then tapped. Click the Calculate button to update the machining operations cost results. 13. The Part feature details group box contains inputs for the surface area generated by various machining processes. This information can either be entered directly into these fields or it can be estimated using the geometry calculator. Normally, the machining cost is not very sensitive to changes in this surface area information. For this reason, it is intended that rough estimates for these area inputs would be entered without use of the geometry calculator. However, for completeness, this tutorial will guide you through completion of the entire geometry calculator for this part.

Using the Geometry calculator to define the part volume and machined areas. 1. Open the geometry calculator by clicking the

toolbar button.

2. On the Part volume tab we will approximate the volume of the finished part by first adding cylinders for the part’s flanges and center section. Click the button on the toolbar at the left side of the window to add a cylinder to the geometry chart. Name the cylinder large flange. 3. Enter a length of 0.8 inches and a diameter of 4 inches in the dimensions panel on the right side of the screen. 4. Add another cylinder to the geometry chart and name it center section. Enter a length of 4.4 inches and a diameter of 2.4 inches.


Chapter 6 / DFM Concurrent Costing User Guide 5. Add a third cylinder to the geometry chart and name it small flange. Enter a length of 0.8 inches and a diameter of 3 inches. 6. We will also subtract cylinders to account for the holes that pass through the part’s center and large flange. Add a fourth c ylinder to the geometry chart and name it center hole. Subtract the cylinder by clicking the button in the middle of the shape group box. Enter a length of 6 inches and a diameter of 1.5 inches. 7. Add a cylinder to the chart and name it flange hole. Subtract the cylinder and enter a length of 0.8 inches and a diameter of 0.2 inches. Beneath the geometry chart, change the repeat count to 4. 8. Obrounds are subtracted to account for the slots that are milled in the part’s center section. Add an obround to the chart and name it button at the right of the shape group box. Enslot. Click the ter a thickness of 0.45 inches, a length of 2.5 inches, and a width of 0.75 inches. Change the repeat count for the obround to 4. 9. Click the Part volume entry at the top of the geometry chart. Note that the part volume total shown beneath the chart is 20.74 cubic inches. This total will be transferred to the Quick estimate later when the transfer is completed. 10. Click the Finish turned area geometry tab. On this tab we will approximate the surface area generated by the finish turning done on the outside faces of the large and small flanges, the inside face of the large flange, and the central hole. Click the button to add an annulus area to the chart and name it outside face - small flange. Enter an inside diameter of 1.5 inches and an outside diameter of 3 inches. 11. Add another annulus area to the chart and name it outside face large flange. Enter an inside diameter of 1.5 inches and an outside diameter of 4 inches.

For a rotational part, a hole is considered secondary when its diameter is less than one tenth the diameter of the part envelope. For other shapes, a hole is considered secondary when its diameter is less than one tenth the mid-dimension of the part envelope.

12. Add a third annulus area to the chart and name it inside face large flange. Enter an inside diameter of 2.4 inches and an outside diameter of 4 inches. 13. Add a cylindrical area to the chart and name it center hole. Enter a length of 6 inches and a diameter of 1.5 inches. 14. Click the Drilled area geometry tab. This tab will be used to define the cylindrical area of the four small secondary holes drilled into the large flange. Add a cylindrical area to the chart and name it flange hole. Enter a length of 0.8 inches and a diameter of 0.2 inches. Change the repeat count to 4.


DFM Concurrent Costing User Guide / Chapter 6 15.Click the Threaded area tab. This tab will be used to define the cylindrical area of the four threaded holes on the large flange. Add a cylindrical area to the chart and name it flange hole threads . Enter a length of 0.8 inches and a diameter of 0.2 inches. Change the repeat count to 4. 16. Click Transfer and Close from the Geometry menu to transfer geometry totals to the Quick estimate and return to the Machining operations response panel. Check that the values shown in blue fields in the Part feature details group box have been transferred as shown below.

Completing the Quick estimate 1. Leave the Part surface finish dropdown set to Average. Enter 0.75 inches for the average diameter of milling cutters and enter 0.2 inches for both the Average diameter of drilled holes and the Average diameter of threaded features.

2. Press the Calculate button to complete the Quick estimate. Click the Stock process entry on the Process chart and note that the total cost result is $45.59. 3. Click the Machining operations entry on the Process chart. Click the Display machine properties checkbox. Note that a Haas SL-10 CNC lathe has been automatically chosen to turn this part and to mill, drill, and tap the secondary features. All default properties of this machine have been taken from the software’s machine library.

Open a completed analysis file 1. Open the completed analysis file by selecting Open from the File menu. In the Open dialog, open the cylinder.dfm file that is installed in \data\samples. There is no need to save the Quick estimate created during this tutorial. 2. In the cylinder.dfm file, there are two analysis tabs. The first tab, Quick estimate, contains the Quick estimate you will have created during this tutorial. The second tab, Full analysis, contains a machining full analysis of the same part.


Chapter 6 / DFM Concurrent Costing User Guide 3. To compare the Quick estimate and the Full analysis, click the Graphs menu and then click Cost Breakdown. Select Bar Chart and highlight both analyses in the Select analysis dialog. Click OK to display the cost breakdown comparison graph shown below.

4. Note that the material cost estimate for the Full analysis and the Quick estimate are identical. This is because the method used for estimating material cost is the same for both types of machining analyses. Also note that the Quick estimator has overestimated the setup cost by 35.6% ($0.80 versus $0.59). This is because the number of different cutting tools required to machine the part is not defined by the user in the Quick estimate and is estimated internally. Each different cutting tool requires additional setup time so the comparison shows that the Quick estimator’s estimate of the num ber of different cutting tools required is a bit too high for this particular part. Also note that the Quick estimator has underestimated the Process cost by 14.6% ($8.81 versus $10.32). This is because the number of cutting tool movements must be estimated internally by the Quick estimator. Each movement of the cutting tool results in additional costs for non-productive time so the comparison shows that the number of cutting tool movements estimated by the quick estimator was a bit too low for this particular part. The cost of rejects is about the same for the two analyses.


DFM Concurrent Costing User Guide / Chapter 6 5. Click the toolbar button to display the cost breakdown graph as a stacked bar chart.

6. Note that the total part cost estimated by the Full analysis is $46.9 while the Quick estimate for the same part is $45.59. This indicates an overall underestimate of 2.8% in the Quick estimate of total part cost.

Normally, the machining cost is not very sensitive to changes in the surface areas generated by machining operations. This means these areas can be roughly defined when completing a Quick estimate. In fact, if all the default values for these areas were used, the Quick estimate of part cost would be $49.26 which is only 8.05% larger than the completely defined Quick estimate. The partially defined Quick estimate overestimates the part cost by only 5.03% when compared with the full analysis.






Chapter 7

Machining cell process A machining cell is normally a group of machines arranged so that they are physically close to one another. The parts output from the first machine in the cell feeds the parts input to the second machine in the cell, whose parts output feeds the third machine, and so on throughout the cell. Two types of machining cells are commonly used; what can be called non-dedicated and dedicated machining cells. Non dedicated machining cells are used to process families of similar parts and have the advantage that the machines within the cell are set up once to process all of the similar parts made in the cell. Non-dedicated machining cells are commonly used when groups of similar parts are made in lower production volumes. On the other hand, dedicated machining cells are used to process a single type of part. Dedicated machining cells have the advantage of decreased part handling and increased production rate and are normally used for parts made in higher production volumes. The following tutorial demonstrates how you can compare the cost of a part machined in a dedicated machining cell with one part machined using individual machine tool setups. Normally, to make this comparison, you would first perform a normal machining analysis for your part. However, for this tutorial, we will use one of the analyses provided in the sample files. 1. Start DFM Concurrent Costing and select Open from the File menu. In the Open data file dialog choose the machined or cast part.dfm file from the \data\samples folder and click the Open button. 2. On the Stock sep. setups analysis tab, change the life volume to 100,000 and click Calculate. 3. Right click the Stock sep. setups analysis tab and select Copy Current Analysis from the pop-up menu. Name the new tab Cell.


Chapter 7 / DFM Concurrent Costing User Guide 4. Click the Milltronics GL6 turning center entry on the Process chart and note in the response panel on the right that the cycle time per part is 907.31s. Click the Haas HMC HS-1 entry on the Process chart and note that the cycle time per part is 268.35s. Click the Kitamura CNC drilling center and note that the cycle time per part is 113.18s. A machining cell with these machines and cycle times per part would produce a completed part every 907.31s; the cycle time for the turning center which is the bottleneck machine. This indicates a rather poorly designed machining cell because the milling machine and drilling center would be idle for much of the time. Our objective in the design of this machining cell is to balance the cycle times per part for the individual machines in the cell in order to minimize machine idle time. In this case we will consider arranging two turning centers in the machining cell to share the work of one and reduce the cycle time of the bottleneck machine. 5. Right-click the Milltronics GL6 turning center entry in the Cell analysis and select Insert Machine Tool Setup from the pop-up menu. 6. In the Add Machine Tool dialog that appears, expand the Lathes category and double-click the Milltronics GL6 turning center to add that machine to the analysis. Close the Add Machine Tool dialog by clicking the button in the upper right hand corner of the dialog. 7. Drag and drop the following operations from the first turning center to the new turning center: The second rough cylindrical turn operation Drill single hole Finish cylindrical bore

The last two finish face operations


DFM Concurrent Costing User Guide / Chapter 7 8. Click the Setup/load/unload operation beneath the first Milltronics GL6 turning center setup and change the number of reversals to 0. 9. Click the Setup/load/unload operation beneath the second Milltronics GL6 setup and select a 3-jaw chuck workholding device. Click Calculate. 10. Now note that the cycle times for the four setups are 436.99, 475.54, 268.35 and 113.18s respectively. Although this machining cell is still far from balanced, it is significantly improved from the cell that contained only one turning center. 11. Click the Generic stainless steel machined/cut from stock entry on the process chart and click the Select process and material button. 12. In the Process and Material Selection dialog, expand the Machining or cut from stock process category. Select the Cell machining process. For the material, select Generic stainless steel from the Stainless steel category and click OK .

Study the machining cell results 1. Click the Machining cell results entry on the Process chart and observe the results displayed in the right hand column.

2. Note that the program has selected the longest of the four machine cycle times for the Cell cycle time. Also note that the Cell rate is the sum of the machine rates for all machines within the cell plus the rate for the number of cell operators required. The Automatic transfer device rate field allows you to simulate a cell where transfer (load/unload/reversals) between machine tools is carried out automatically – with a robot for example. 3. Click Cost Breakdown from the Graphs menu and select Bar Chart . In the Select analyses dialog that appears, select the Stock sep.setups and Cell analyses and click OK .



4. The total cost per part for the part produced in a cell is $52.63 compared with $54.26 for the part produced on separate setups. However, the cost of material is $35.77 and therefore the nonmaterial cost savings from machining in the cell is just under 9% ($16.86 compared with $18.49). 5. From the File menu, select Revert to Saved to leave the file in the original condition in case you wish to repeat the tutorial in this chapter.



Chapter 8

A deep drawing analysis When a cup or box shaped part is produced from sheet metal, one possible processing alternative is deep drawing. In this tutorial, we will examine the deep drawn part shown below. This part has also been analyzed in the deep drawn part.dfm sample file installed with the software.

Part description

From the File menu, choose New or on the toolbar click:

1. Start a new analysis in DFM Concurrent Costing. 2. Enter drawn part for the Part name in the Part Description panel. Accept the default value for Life volume of 100,000. Choose the box envelope shape and enter dimensions as shown below. Also note that the Z forming direction is chosen.

3. With this data entered, click the Select process and material button.

A deep drawing analysis / 59

Chapter 8 / DFM Concurrent Costing User Guide 4. Choose the Separate operations process in the Sheet metal deep drawing category. Open the Carbon steel category and click the Generic low carbon steel material. Green indicators are shown for the process and material chosen which means the combination presents no practical limitations. Click the OK button on the dialog to accept the choices and return to the main window. 5. The Separate operations drawing process entry is now highlighted on the Process Chart. The default information in the Response Panel on the right has been automatically generated based upon the data entered so far and information contained in the software’s Machine and Material libraries. This default information will now be refined in order to generate a more accurate cost estimate. 6. We accept the default information in the Basic data group box. In the Part basic data group box, edit the base length and width as well as the corner, bottom, and flange radii as shown below.

7. Click the Calculate button in the Cost results box, to update the estimate. 8. You may wish to save this file for later viewing. Choose Save from the File menu, and supply a file name. 9. Accept the default information in the Operation data group box. Scroll down to the Additional setups group box if necessary. Enter 1 for the Hole punching response, as shown on the next page.

60 / A deep drawing analysis


10. Click Calculate to add the hole punching setup to the Process Chart. 11. The remaining Responses Panel group boxes are used for definition of the part’s geometry. This information can either be entered directly into these responses or the software’s Geometry Calculator can be used as shown in the following section.

Completing part geometry data

Another means of supplying geometry data to a DFM analysis is to import it from a CAD drawing. See the Responses and Results section in Chapter 1 of this User Guide.

1. To specify the part geometry data, click the toolbar button to open the Geometry Calculator. Notice the three tabs under the geometry chart.

These correspond to the geometry sections Part geometry, Trim data and Punch holes 1 data on the main window. 2. View each tab in turn to see instructions for adding geometry elements. Notice the toolbar(s) on the left side of the window. The buttons on the toolbars are used to add elements to the geometry chart. 3. On the Part tab, we will approximate the volume of the part, excluding the holes, by defining the flange and box portions of the part separately. For the flange, click the block button to add a block entry to the geometry chart. Rename the block entry flange. 4. Click the Rectangular Tube in the Shape group and enter a flange width of 0.5 inches, a flange thickness of 0.07 inches, a part width of 4 inches and a part length of 6 inches as shown on the next page.



5. Add another block entry to the geometry chart and rename it box. In the dimensions panel, select the hollow box in the Shape group. Enter a wall thickness of 0.07 inches, a height of 0.93 inches, a width of 3 inches, and a length of 5 inches. The Volume as drawn and trimmed total could be further refined by including elements to describe radii on the edges of the box. However, these small refinements do not affect part cost significantly and for most practical purposes, an approximate volume is sufficient.

6. Click the Part entry at the top of the geometry chart. In the totals below the chart, the part’s Volume as drawn and trimmed is 2.626 cubic inches. This total will be transferred to the Responses Panel in the analysis when we take this transfer step later.

7. Click the Trim geometry tab to define the part perimeter trimmed after drawing. Add two of the Line - length specified elements using the top button on the perimeter toolbar. Without renaming the entries, enter a length of 6 inches for one and a length of 4 inches for the other. Change the repeat count of both entries to 2. Click on the top entry Trim on the geometry chart and note the Trim perimeter totals 20 inches.


DFM Concurrent Costing User Guide / Chapter 8 8. Click the Punch holes 1 tab to define the two large holes and four small holes punched in the part. Click the circular hole on the tool bar containing the gray shapes to add a round hole to the geometry chart. Enter a hole diameter of 1 inch and change the hole’s repeat count to 2. Add another round hole to the geometry chart, change its repeat count to 4, and enter a diameter of 0.25 inches. 9. Click the Punch holes 1 entry at the top of the geometry chart and note the software has calculated the following totals.

The blue toolbar button area shapes on the furthest left toolbar are used when defining an irregular shape. In defining irregular shapes, sometimes it is necessary to both add and take away area elements.

10. The geometry definition is now complete. Click Transfer and close from the Geometry menu to transfer geometry totals to the Responses Panel in the analysis. 11. Click Calculate to update the cost results and note that the total cost of the part is $1.45.

Combining operations In some cases, operations performed on two separate setups can be combined so they are done in a single compound tool on a single setup. Combining operations normally increases the cost of tools while decreasing the cost for processing. The software will quantify this increase and decrease in costs and help you determine if combining operations is worthwhile in terms of the total cost of the part.


Chapter 8 / DFM Concurrent Costing User Guide After considering the possibility of combining various operations listed on the process chart, we can see two possibilities for combining. Hole punching could be carried out during the flange trim operation using a trim tool that incorporates punches to create the holes during trimming. The two restrike operations could also be combined using a tool that would shape the flange and bottom radii simultaneously. These possi bilities will now be investigated to determine if combining these operations will result in a lower part cost overall. 1. Click the Punch holes operation on the Process Chart. In the Responses Panel you see the Process combination group box as shown below.

2. Click the Combine button and you are shown a list of operations that could conceivably be combined with the punch holes operation.

To review combined operations, highlight the Compound operation on the Process Chart. The Included operations group box on the Response Panel lists operations performed on the setup. Click the Separate button in the Process combination group box to separate the combined setup.

3. Select the Flange trim operation and click OK to close the dialog. The punch holes and flange trim setups are replaced with a single setup and a compound operation. Click the Calculate button to update cost results. 4. Highlight the top-level entry on the Process Chart, labeled Generic low carbon steel sheet metal part . In the Cost results pane, notice that the total cost per part has decreased from $1.45 to $1.38. This indicates combining operations is beneficial in this case because the overall cost per part has decreased. 5. Click the Restrike flange radius operation on the Process Chart and click the Combine button on its Responses Panel. Select the Re strike bottom radius operation from the Combine operations dialog and click OK . Click the Calculate button to update cost results.


DFM Concurrent Costing User Guide / Chapter 8 6. Highlight the top-level entry on the Process Chart and notice that the total cost per part has decreased from $1.38 to $1.36 as shown below. Combining operations is also beneficial in this case.

Comparing to another process The design of a manufactured part depends on the material and process used to make it. For this reason, during early stages of product development, it is useful to economically compare various strategies for manufacturing parts. A part which is stamped and bent from sheet metal may serve the same function as the drawn part, possibly at lower cost. This possibility will now be economically investigated. 1. From the Analysis menu, choose Copy Current Analysis. A copy of the deep drawing analysis is made and placed on a new tab. Rename the tab Compound die. 2. Click the Select process and material button to open the selection dialog. Choose Compound die from the Sheet metal stamping category; and select the Generic low carbon steel material from the Carbon steel category. 3. Click the OK button. Click Yes when the ‘Switching processes will delete the data that does not apply to the new process’ warning ap pears. A new Process Chart is created and the data entered into the drawing analysis has been copied to the new stamping analysis. 4. Much of the data imported from the drawing analysis is placed in the Compound die operation data group box shown on the next page. Data that has been imported, or calculated based upon imported information, are shown in responses with a blue background.

The white background in a field means that field has not been edited and is not locked.



If more accurate geometry is desired, it can be input directly on the Responses Panel or developed using the Geometry Calculator.

5. The Perimeter of blank was not specified in the drawing analysis so that information has not been imported. The default value of 28 inches, which is estimated from the part’s envelope shape and dimensions, is very close to the perimeter sheared on the box. For this reason we will accept this default value and continue with our analysis. 6. The stamped part will require eight bends to form the box and flange. These bends will all be made on a single press brake. Enter 1 into the Press brake response in the Additional setups box to add the press brake. Click Calculate to update the Process Chart. 7. Enter 8 in the number of bends response in the Press brake brake 1 group box. Four of these bends are each 3 inches long and the remaining four of these bends are each 5 inches long. Enter this total of 32 inches into the Length of bend lines response as shown below.

8. Click Calculate to update the cost results. 9. Click Stacked Bar Chart in the Graph Cost Breakdown menu to make a graphical cost comparison of the stamped and drawn parts. In the Select Analyses dialog, click the first analysis, and then hold your left mouse button down and drag to highlight the second analysis. Click OK to display the graph. →

66 / A de deep ep dr dra awi wing ng an anal alys ysis is

DFM Concurrent Costing Costing User Guide / Chapter 8

10. This graph shows the drawn part costs $1.36 while the stamped part costs $1.21 for an overall cost savings of 15 cents with the stamped part. The stamped part also requires just about one quarter the upfront investment in dedicated tooling. However, the stamped part has open corners that are not as aesthetically pleasing as the closed and rounded corners on the drawn part. In addition, the small holes on the flange of the drawn part would probably have to be relocated to the center of each bent lip on the stamped part. If these characteristics of the stamped part meet design objectives, a cost savings of about 15 percent can be realized by going with the stamped part.



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68 / A de deep ep dr dra awi wing ng an anal alys ysis is


Chapter 9

A fabricated assembly analysis The DFM Concurrent Costing software can be used to evaluate various strategies for the design of a manufactured item. Frequently, one design strategy might involve breaking the item up into several parts and utilizing joining processes such as welding or riveting to create a fabricated assembly. DFM Concurrent Costing can be used to make cost comparisons to determine if a fabricated assembly is more cost effective than manufacturing the item as a single part. Fabricated assemblies typically become most cost effective when producing the item as a single part results in significant material waste or a part geometry that is very difficult to manufacture. Fabricated assemblies can also be more cost effective when produced in lower volumes because in some cases, the cost of tooling is less. The analysis uses the same database of assembly times as the Design for Assembly (DFA) software. However the procedure for analysis has been simplified so that the responses required only include those that are significant in estimating the assembly cost. Also, the program estimates the distance to the locations of the parts in the assembly area de pending on the size of the assembly. This eliminates the need to guess the distances to acquire parts during the analysis. However the results of an analysis will be close to those obtained from the DFA program. This tutorial illustrates the estimation of the total cost of manufacture of a welded fabrication, consisting of 4 parts welded together, shown below. The complete analysis is contained in the sample file welded assembly.dfm included with your installation of DFM Concurrent Costing.

A fabricated assembly analysis / 69


Begin the analysis The Process Chart for an assembly fabrication starts with a definition of some general parameters and the primary material. 1. In a new analysis, complete the part description as shown here:

2. Complete the envelope shape selection and dimensions as below:

The Approximate envelope dimensions are those for the completed assembly.

3. Accept the default forming direction. Rename the Process Chart tab from Original to weldment, by clicking the tab to put it into edit mode and then type the new name. 4. Click the button Select process and material . 5. In the Process and material selection window, choose Assembly fabrication for the process. For the material, open the Carbon steel category and choose Generic low carbon steel. 6. Click the OK button to return to the main window with the responses for the fabrication process shown on the right panel.

70 / A fabricated assembly analysis

DFM Concurrent Costing User Guide / Chapter 9 7. In the Basic data box enter $ 0.05 in the response Scrap value of finished assembly. The Assembly labor rate of $30.00 will be ap plied to all the operations used in creating this assembly.

8. There are 4 sheet metal parts to be welded together. The first process step is to set up the assembly jig to hold the first part. We can start with the operation of setting up this jig. Click the Insert Operation toolbar button. 9. In the Library Operations dialog that opens, click the plus sign, if necessary, to see the operations in the Welded fabrication category. Double-click the Setup welding jig operation to add it to the Process Chart. The cost of the jig is applied to the tooling cost for the part.

The assembly labor rate, set at the process level as we saw earlier, will be applied to the setup time. Click the Calculate button to update the Cost resuts box.

10. We now add the first part. This part has been analyzed using DFM Concurrent Costing, and the cost information from that analysis is used here. To add a DFM part, click the Import Analyzed Part toolbar button.

Or right-click in the Process Chart and choose Insert Operation from the menu. Or from the Analysis menu choose Insert Operation.

You can leave the Library Operations dialog open, and move it out of your way by grabbing its title bar with the mouse, and dragging. Or you can “dock” the dialog by clicking the title bar and dragging it under the toolbar on the main window to the left of the Process Chart. To float it, click and hold its title bar while moving it off the docked position.

The white Enter Part button is used when the part has not been analyzed in DFM Concurrent Costing, such as with a purchased part. Both kinds of parts can be added from the Analy sis menu, or the rightclick menu in the Process Chart.


Chapter 9 / DFM Concurrent Costing User Guide 11. You are presented with an Open dialog. Navigate to the directory where the DFM sample file welded assembly.dfm is located, the samples subfolder of the DFMA Data directory, by default. Click the Open button. 12. Because the file welded assembly.dfm contains more than one analysis, you are presented with the tab names of each analysis. Click the second name, base, and click OK to add the base to the Process Chart.

13. The Response Panel for the base has two group boxes, one Basic data, the other Part data. Most of this data has been imported from the existing DFM analysis, and is not editable. Click Calculate to see the cost breakdown for the added part as shown in the Cost results. 14. The next step in the analysis is to acquire the base and position it in the jig. If necessary, re-open the Library Operations dialog ( Analysis menu Insert Operation). Double-click the operation Get parts and position in jig (Welded fabrication category.) Close the Library Operations dialog. →

15. In the Data group box, enter the dimensions of the base: length 4, width 4, and depth 0.25. There will be no problems acquiring the base or inserting it into the jig, so we will accept the defaults for the other operation fields. Click Calculate.


DFM Concurrent Costing User Guide / Chapter 9 16. Now add the DFM part back plate from the welded assembly.dfm file as you did the base and click Calculate. 17. Select the Get parts and position in jig operation and click the Copy toolbar button. Now select the back plate entry and click the Paste toolbar button. Edit the dimensions: length 5, width 3, and depth 0.25. Again, there will be no problems acquiring the back plate or inserting it into the jig. Click Calculate.

The copy and paste buttons are on the toolbar:

Or find them in the rightclick menu in the Process Chart.

18. Now add the two identical gussets to the Process Chart. From the welded assembly.dfm file, add one gusset and change its repeat count to 2. Click Calculate.

19. Copy and paste the operation Get part and position in jig as before. Edit the dimensions: length 3, width 2.25, and depth 0.25 and again, change the Repeat count response to 2 (the two gussets will be acquired simultaneously). Also check the box for Part not easy to align. Note that the time for the assembly step is updated after each response as shown below.

Click Calculate to update the cost results.


Chapter 9 / DFM Concurrent Costing User Guide 20. Now we need to secure the parts in the jig prior to welding them. Add the operation Secure parts in jig and change the Number of toggle clamps to 4. 21. Now the parts are to be welded together. With the Secure parts in jig entry highlighted on the Process Chart, double-click the Robot MIG fillet weld operation in the Welded fabrication category. It is added to the Process Chart.

21. The edits needed to the responses for the welding operation are Number of welds 8 and Total welded length 22 inches. Click the Calculate button to update the cost results.

22. To complete the manufacture of the welded fabrication, there is an additional operation needed. From the Welded fabrication list in the Library Operations dialog, double-click Remove assembly. Click Calculate again.


DFM Concurrent Costing User Guide / Chapter 9 23. Finally, we will inspect the finished product. In the Library O perations dialog, expand the Inspection entry and double click Inspect visually to add it to the Process Chart. Accept the rejects percentage of 0.5. Change the Inspected area to 88.15 square inches and click Calculate. 24. Close the Library Operations dialog. To review the Cost results for this assembly fabrication analysis, click the top level of the Process Chart. The total cost per part is $5.84.

Viewing the completed fabrication analysis We now turn to the completed sample analysis of the bracket fabricated assembly. In your Dfma installation, open the welded assembly. dfm file in the Data\samples subdirectory. The completed sample file, which contains the weldment analysis as well as an analysis for each of its parts, also has a casting analysis of the same part. For all the analyses there is a picture for each step. 1. To easily view the development of the part through pictures, click the border of the picture and drag it off the DFM window and onto the desktop. 2. Click a part entry on the Process Chart for any tab, to view a picture of the processing of the part at that stage. 3. To return the Picture box to the DFMA window, drag and drop it on the Responses panel. If you close the Picture box when it is floating, you can reset it on the DFMA window by checking Show Picture Box in the Window Layout dialog, available from the Tools menu.



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Chapter 10

An automatic assembly analysis The Automatic Assembly process program allows you to estimate the cost of assembly of a product using high-speed automatic assembly machines. For comparison purposes, the program will simultaneously estimate the cost of assembling the product on a manual assembly line.

Our sample analysis is for a small plate assembly consisting of eight parts. 1. Start a new analysis and enter plate assembly for the Part name and a Life volume of 30,000,000. 2. The overall shape of this assembly would be a solid cylinder and the overall dimensions are 0.876 inches for the length of the envelope parallel to the cylinder axis, 0.1 for the average thickness and 2.4 for the diameter.

Automatic Assembly / 77

Chapter 10 / DFM Concurrent Costing User Guide 3. Click Select process and material and select Automatic assembly. You are not required to select a material for this process. Click OK and the main Response screen will be displayed. Note that in the left panel, in addition to the entry for the Automatic assembly process there is an entry entitled Transfer system and downtime. Once you have entered the operations, highlighting this entry will display the results of the analysis for two types of automatic assembly machine and for a manual assembly line. As you add operations for the feeding, orienting and insertion of the various parts in the assembly and for any other operations you add, these results will be continually updated.

In the right Responses panel you will now review the data for the overall requirements of the assembly machine and the basic costs of assembly equipment.

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DFM Concurrent Costing User Guide / Chapter 10 4. Overall plant efficiency, %: As with the other processes in Concurrent Costing, we allow you to specify an overall plant efficiency. In this case we will accept the default of 85%. We should note, however, that this figure will not include the additional downtime, special to automatic assembly machines, where stoppages occur due to faulty parts jamming in feeders or insertion devices. 5. Equipment payback, months: An automatic assembly machine is generally a one-of-a-kind special-purpose machine. Consequently, when the economics of an assembly machine are considered, the calculations are usually based on an equipment payback period. For automatic assembly machines this payback period usually varies between eighteen months and three years. In our example we shall assume an equipment payback of 36 months. 6. Shifts worked per day: This value (1, 2 or 3) will be used, together with the payback period and the overall plant efficiency, to estimate the cost per unit time for the assembly equipment. Assume 2-shift working for this analysis. 7. Manual assembly worker rate, $/hr : This is the cost per unit time for a manual assembly line worker or for a worker performing manual assembly operations on an automatic assembly machine. Accept the default of 30 $/hr. 8. Assemblies per cycle: In automatic assembly machines, assemblies are built on specially designed workcarriers. Sometimes, workcarriers are designed to hold more than one assembly. In our analysis, we will assume that only 1 assembly is delivered per machine cycle. 9. Desired assembly rate per minute: This is the rate, in assemblies per minute, for which the automatic assembly machine is to be designed. This rate together with the number of assemblies per cycle will determine the cycle time for the machine. For this example, we will enter a rate of 30 assemblies per minute. With one assem bly per cycle, this will mean that the machine will cycle every two seconds and produce an assembly every two seconds when it is working. 10. Parts causing stoppage and Average down-time per stoppage: You should make every effort to obtain reasonable values for these two factors, based on your experience with similar automatic assembly equipment. In this case we will accept the defaults. This means that, on average, two parts in every thousand will be defective and will cause a machine or workstation stoppage. The average downtime per stoppage of 30 seconds represents the average length of time that it will take a machine supervisor to recognize and locate the cause of the stoppage, clear the faulty part from the feeder or workhead and restart the machine.


Chapter 10 / DFM Concurrent Costing User Guide 11. Technician rate, $/hr : This is the cost per unit time for a technician overseeing an automatic assembly machine and correcting machine or workstation faults. We will accept the default value of 40 $/hr. 12. Other responses: We will accept the defaults for the various basic equipment costs.

Analysis of Individual Parts

Editing the number of decimals in the Window Layout dialog will change the decimal display for results on the main window, graphs and reports. Change the number of decimals for operation variables in the Operation Library Formula Window.

We now analyze each individual part for the cost of feeding and insertion into the assembly. During the analysis we will define whether the part is inserted and then secured later during the assembly process or whether it is inserted and secured immediately. Since the cost of automatic assembly is usually quite small, select Tools from the menu, select Window Layout and change the No. of decimals to 5. Click OK . This program allows you to estimate the total cost of assembling your product or subassembly. However, you have the option of including the costs of the parts. For this analysis we shall only determine the cost of assembly and will not include the manufacturing costs of the individual parts.

As mentioned earlier, assembly machines are designed to transport workcarriers on which the assembly is built. These workcarriers are designed to accept and, where possible, hold the assembled parts in position. Since we name the operations in the order in which assembly proceeds, we start by inserting the two nuts into prepared recesses in the workcarrier.


DFM Concurrent Costing User Guide / Chapter 10 Insertion of Nuts

1. We first decide whether the basic shape of the part is rotational or non-rotational. The envelope that would best fit a nut is cylindrical. In other words this is a rotational part. Select Insert Operation from the Analy sis menu and select Assembly of rotational part from the list of operations. Click Add. Close the Library Operations dialog. The responses for an analysis of the nuts are now displayed.

...or on the toolbar click

2. Specify a part thickness or length of 0.2, a part diameter of 0.344 and a repeat count of 2.

3. Now we respond to questions regarding the symmetry of the part. The first questions refer to end-to-end symmetry. Since the nuts do not require end-to-end orientation and can be inserted either way up into the workcarrier and there are no features required for end-to-end orientation, select button 0 End to end orientation not required . 4. Similarly, for rotational symmetry, the nuts do not require significant rotation about their axes in order to insert them into suitably designed pockets in the workcarrier. Select button 0 Orientation about axis not required . 5. For the nuts, it is assumed that feeding problems do not exist and none of the boxes should therefore be checked.

Even though geometrical features on a part can be used to orient them in an automatic feeding device, they sometimes possess characteristics which make them difficult to feed. For example, a common problem is that parts sometimes will nest together like paper cups or tangle like helical springs, or they may be covered with grease making them difficult to separate. Problems such as these will often involve additional expense in feeder design and development.


Chapter 10 / DFM Concurrent Costing User Guide 6. We now address the problems of part insertion. Here we assume that an automatic pick-and-place workhead will select the parts, delivered by the feeder in the required orientation, and then place them in the workcarrier. Again, we select whether the parts are added and not secured or whether they are added and secured immediately. The nuts are added to the workcarrier but they will be secured to the assembly later. Since the nuts will be retained in the recesses in the workcarrier ready for the next operation none of the boxes relating to insertion need to be checked. 7. Click the Calculate button. Scroll down if necessary to review the results for the automatic feeding and orienting and insertion of the two nuts. First we see that the program has decided that the nuts will be inserted simultaneously at one automatic station. 8. Since we have assumed that there will be one assembly built on each workcarrier and have indicated that the desired assembly rate is 30 assemblies per minute, the machine cycle rate is 30 per minute. However, because we are assembling two nuts at the same station, the desired feed rate from the automatic feeder will be 60 per minute. 9. With the data that we have provided regarding orientation and feeding of the parts, the program has estimated a maximum feed rate from one feeder of 122 parts per minute. However, the actual feed rate from the feeder will be 60 per minute because this is the desired rate. We see that the cost of feeding the parts is displayed together with the insertion operation cost. Adding these costs gives an automatic assembly cost per assembly of $0.00136. You should note that the process cost for the nuts does not include the cost of the transfer device, controls, or the effects of down time due to faulty parts. The costs associated with these factors will be calculated for the entry transfer system and downtime.

10. Also displayed are the costs of the feeder and workhead. We specified a basic feeder cost of $5,000 and since one feeder can supply parts at the required rate this will be the cost of the feeder for the nuts. However, since we are inserting two nuts at one station, a more expensive workhead costing $20,000 would be required.



11. The program has estimated the manual assembly time and cost for inserting the nuts. These figures are not displayed but will be used in the final calculation to compare the cost of assembly using a manual assembly line. Also, as we will see later, if it is found that manual handling is less expensive than automatic handling, manual assembly would be assumed. 12. In order to keep track of our analysis for this assembly we should edit the names of the entries as we add them. In this case we should edit Assembly of rotational part to insertion of nuts . 13. It would be a good idea to name and save our analysis at this stage. Select Save from the File menu. We will give the analysis the name plate assembly tutorial . Insertion of Washers

Operation names can be edited after they are added to the Process Chart. To edit, click once on the entry name on the Process Chart or right-click the entry name and select rename. The Operation Library will still recognize renamed operations during a reload ( File Reload Data) function. →

1. With the entry insertion of nuts highlighted, add another operation for the Assembly of a rotational part . 2. The part thickness or length is 0.05, the part diameter is 0.3 and the repeat count for the washers is 2.


Chapter 10 / DFM Concurrent Costing User Guide 3. Like the nuts, the washers do not require orienting end-to-end (can be placed in the workcarrier either end up) and do not require orienting about their axes. Also, there would be no feeding problems. The washers would be added but not secured and there would be no insertion problems. 4. Click Calculate to view the results. We see that the results are almost identical to those for the nuts except that we could obtain a slightly higher feed rate from the feeder.

5. Change the entry to read insertion of washers . Insertion of Plate

1. With the insertion of washers entry highlighted, add a library operation for a rotational part. 2. The part thickness or length is 0.063, the part diameter is 2.4 and the repeat count is 1. 3. The part can be placed in the workcarrier either end up so end-toend orientation is not required.


DFM Concurrent Costing User Guide / Chapter 10 4. The part must be placed in the workcarrier so that the two holes, which will eventually accept the screws, are located above the washers and nuts. These two holes are the features that determine the orientation of the plate about its axis. However, they cannot be seen in the outer shape of the silhouette of the part, so we select button 6 Asymmetry too small or cannot be seen. We can assume there are no additional feeding problems for the plate but we should indicate that, once the part has been inserted and properly oriented in the workcarrier, it will require holding down and was not easy to align and position. Check these boxes in the Insertion group. 5. Click Calculate and see that a warning is presented stating that automatic feeding is not practical and manual assembly is assumed. The plate will require 5 manual stations to maintain a machine cycle rate of 30 per minute (a cycle time of 2 seconds) because the estimated manual assembly time is 8.56 seconds. Also, we note that the cost for this entry will be $0.07133 which is significantly higher than the costs we saw for automatic assembly of the nuts and washers.

We will find that the program determines that these parts cannot be economically fed and oriented. This is because their orientation could not be maintained in a delivery track even if it were possible to orient them within the feeder. However, we continue to answer the remaining questions because the program must estimate the cost of manual handling and insertion for this part.

6. Edit the entry to manual insertion of plate .


Chapter 10 / DFM Concurrent Costing User Guide Insertion of Bearing housing

1. With the entry manual insertion of plate selected, add an operation for Assembly of non-rotational part . If we enter the dimensions in the incorrect order, a warning will ap pear asking us to re-enter them.

2. Enter the dimensions of the rectangular envelope that will enclose the part. It is important to realize that the part envelope length must be larger than the part envelope width which in turn, must be larger than the part envelope depth. Thus, we enter 2.125 for the length, 0.563 for the width and 0.4 for the depth. The repeat count is 1. 3. Referring to the picture in the Data group we also need to recognize that the X-axis of the part is parallel to its length, the Y-axis is parallel to its width and the Z-axis is parallel to its depth. We must now consider 180 degree rotation of the part about each of these axes in turn. We note that the Y-axis is the only axis for which the part repeats its orientation after rotation of 180 degrees. We check the box for the Y-axis .


DFM Concurrent Costing User Guide / Chapter 10 4. We now view the part along each of its axes. When the part is viewed in the X direction, we see symmetrical projections and check button 3 for the X direction. For the Y direction, accept the default of No main feature defines asymmetry. Also, a groove can be viewed in the Z direction so we check button 4 symmetrical grooves or steps. 5. We assume that the bearing housing does not present any additional feeding problems and that it is added but not secured. However, when it is added to the assembly it must be carefully positioned because there are no features to assist in alignment and positioning and it will require holding down until the screws are inserted. After checking the two appropriate boxes click Calculate to view the results.

Although this part can be automatically fed and oriented, the maximum feed rate from one feeder is only 11 parts per minute whereas we require 30. For this reason, additional funds would be needed for the feeding equipment and, because the part requires holding down after insertion, additional funds would be needed for the workhead.

6. Edit the name of the entry to insertion of bearing housing .


Chapter 10 / DFM Concurrent Costing User Guide Insertion of Screws

1. With insertion of bearing housing selected, add an operation for the assembly of a rotational part. 2. The part thickness or length is 0.65 and the part diameter is 0.25 and the repeat count is 2. 3. The screws require end-to-end orientation but can be fed suspended by their heads in a slot. We select button 1 Part can be fed in slot . 4. The screws do not require orientation about their axes because the automatic screw drivers will locate the slot in a screw head. 5. There are no additional feeding problems but we must select Part secured immediately for the insertion type. An additional drop down appears for the Securing method and we select Screw fastening . There is no provision on these screws for a pilot point or other feature to facilitate alignment and positioning so we check the box part not easy to align and position. 6. After clicking Calculate we can see that a single feeder can feed these parts at a rate of 83 per minute but, because the parts are not easy to align and position and two workheads are required, the cost of equipment is fairly high. 7. Name the entry insert and fasten screws.

Results 1. Click the entry transfer system and downtime to view the results of the analysis. We note that an automatic assembly machine will have four automatic stations and five manual assembly stations giving a total number of stations of nine. We have not added stations for inspection or packing, etc.



For a synchronous assembly machine, the total equipment cost is approximately $219,000 with a significant down time due to faulty parts of over 17%. This gives us an actual assembly rate of just over 21 per minute due to overall plant efficiency and the down time due to faulty parts. This figure is about two thirds of the desired assembly rate of 30 per minute and it would take about six years to complete the production of 30 million assemblies at a total assembly cost for each assembly of $0.225. We should realize that this cost is rather high due to the fact that we required 5 manual assembly stations for the insertion of the plate.

Note that the tooling investment in the Result box is zero. This is because the tooling investment in Concurrent Costing was intended to represent the cost of tooling for the manufacture of parts, whereas an assembly machine is treated like an injection molding machine or a machine tool even though it is a special-purpose one-of-akind piece of equipment.

For the non-synchronous assembly machine the equipment cost is over twice that for the synchronous machine. However, since the down time due to faulty parts is less and the average assembly rate is higher, the assembly cost per assembly is slightly less than that for the synchronous machine.

If we add parts to our analysis, the tooling investment for the manufacture of the parts will be displayed in the Results box together with the material, set-up, and process costs.


Chapter 10 / DFM Concurrent Costing User Guide For a manual assembly line, the average assembly rate is the highest and is only less than the desired assembly rate due to the overall plant efficiency. The assembly cost per assembly is almost twice that for the non-synchronous assembly machine.

2. Highlight the entry for the Automatic assembly process. Note that the total cost corresponds to the least of the three options, namely the non-synchronous assembly machine. The program has selected the optimum assembly system. 3. Select Cost vs. Life Volume from the graph menu to view this graph. Select all three assembly systems to compare.


We see that manual assembly would be preferred for life volumes up to almost one million and that a synchronous machine (because of its lower investment) would be preferred for volumes up to twenty million. Close the Cost vs. Life Volume graph window.


Redesign of the plate It is clear from this analysis that careful attention should be given to the design of the plate because it required manual assembly, adding considerably to the cost of assembly.

1. Copy the current analysis to a new tab. From the Analysis menu, select Copy Current Analysis and name the tab new design. 2. Highlight the entry manual insertion of plate and add a new operation for the assembly of a non-rotational part.

..or right-click on the tab and select Copy Current Analysis from the menu.

3. We see on the redesign that the edges of the plate have been cropped to correspond to the position of the holes. This new design corresponds more closely to the definition of a non-rotational part whose orientation is defined solely by its dimensions. Enter 2.4 for the length, 1.6 for the width and 0.063 for the depth. 4. Note that the part now has 180 degree symmetry when rotated about any of its axes. Click each of the three boxes. Since there are no features defining the orientation of the part, and since the part will be located properly when it is placed in the workcarrier, no other boxes need be checked.


Chapter 10 / DFM Concurrent Costing User Guide 5. Click Calculate and observe that the part is now automatically fed, oriented and inserted and the automatic assembly cost is minimal. 6. We can now name the entry insertion of redesigned plate and delete the entry manual insertion of plate . 7. Click Calculate and highlight Transfer system and downtime . We now see that the automatic assembly machine would have five automatic stations and no manual assembly stations. We should also note that the assembly cost per assembly for a synchronous assembly machine is one tenth of the previous estimates and much less than the cost of manual assembly. Also, the graph of Cost vs. Life Volume automatic assembly is now economic for life volumes as low as 400,000.



Chapter 11

A printed circuit board assembly analysis Introduction The first step in the manufacture of the printed circuit board assembly is the fabrication of the bare circuit board, often called a printed wiring board. The bare boards can have circuits on one or both sides and in many cases are laminated from several layers with additional circuits in the internal layers. The circuits are generally produced by photochemical processing. Additional steps are needed for the machining of holes through the board, solder masking, legend printing and final PWB testing. The PWB is then populated with electronic components using a com bination of automatic and manual operations. The bare board is first partially populated using equipment for automatic placement or insertion of electronic components. Items that cannot be automatically inserted are then added manually at a workbench or at a semi-automatic machine, which presents items to the operator in the correct sequence for manual insertion. The boards are then soldered using either wave and/or reflow soldering methods. Following this, hand insertion and hand soldering may occur for some items, together with the addition of mechanical parts, such as screws, standoffs, and heat sinks. The assembly of printed circuit boards can be analyzed using operations in the Operation Library, together with the similar operations for any mechanical items. The individual electronic components are not identified, only the number of items with the same package style and numbers of leads. The Operation Library contains time or cost equations for the assembly of various electronic packages by different assembly methods (automatic, robot, semi-automatic, and manual). Various secondary operations specific to printed circuit boards are also included in the library. Analysis of a printed circuit board assembly is based on a list of operations required for its assembly. The figure on the next page shows the upper side of a small circuit board populated with through-hole electronic components. The electronic components on the upper side are inserted first, by either automatic or manual methods. This is followed by wave soldering and cleaning of the board. One connector is then inserted on the lower side of the board and for this reason must be hand inserted and soldered. Some mechanical parts are then added manually. Finally, in this design, the dual-in line-packages (DIPs) are manually inserted into sockets.

A printed circuit board assembly analysis // 93

Chapter 11 / DFM Concurrent Costing User Guide Electronic packages of the same type, with the same number of leads, and inserted using the same method, are grouped together. The table on the next page lists the assembly sequence for the sample board with the packages grouped in this way. You will need to refer to this table during the exercise that follows. The subject of this tutorial is the small video/game card from a PC shown below. This is a double-side mixed surface mount/through hole board. The overall dimensions of the board are length 6.25 inches and width 2.5 inches. The board substrate thickness is 0.062 inches.

In addition to the electronic components there are 9 jumper caps to be added (snap fit) to the connector pins in various places on the board. The board substrate material is the standard FR-4 used for the majority of boards produced. The bare board has solder masking applied to both sides, legend printing on one side of the board and has gold plated contacts along one edge of the board. The minimum conductor spacing is 0.006 inches and the minimum trace (conductor) width is 0.015 inches. There are 502 holes through the board.

94 / A printed circuit board assembly analysis

DFM Concurrent Costing User Guide / Chapter 11 Package Style

Number of leads, pins or pads

Average cost

Quantity

Number of different components

Through Hole

Dual in-line package (DIP)

20

0.10

3

2

Dual in-line package (DIP)

14

0.10

7

4

Single in-line package (SIP)

8

0.05

4

3


6

0.05

1

1


5

0.05

1

1

Radial

2

0.05

3

1

Can

2

0.10

1

1

Connector

10

0.05

3

1

Connector

3

0.05

1

1

Connector

2

0.05

1

1

Connector

24

0.10

1

1

Connector

40

0.15

1

1

Connector

34

0.10

1

1

Connector

25

0.10

1

1

Chip

2

0.01

25

7

Quad Flat Pack

100

2.00

1

1

Surface Mount



Analysis steps 1. Start the analysis by entering PCB Sample for the Part name. Use the default Life volume of 100,000. Select the rectangular block Envelope shape and enter the dimensions as shown below.

2. Now click the Select process and material button. In the left column of processes, choose Printed circuit board assembly. For material, choose FR-4. Click the OK button to calculate some preliminary results.

The Testing entry is the final step in the manufacture of a bare printed wiring board for testing circuit continuity, open circuits, etc. This is carried out using special purpose testing equipment, usually either a bed-of-nails or flying probe tester. In either case a test fixture and test program must be prepared for the specific board type to be tested.

3. Highlight the Bare board process entry on the Process Chart. We will replace some of the default information used in the original estimate to improve the accuracy of the results. Accept the default data for the Basic data group. In the Board processing data group, change the Number of holes to 502 and the Minimum trace width to 0.015 inches. Check the boxes for Gold plated edge connectors, Solder mask required and Legend screen printing . All other defaults can be used. Click the Calculate button and entries for Solder mask and Legend printing will be added to the Process Chart.


DFM Concurrent Costing User Guide / Chapter 11 4. We now select the operations for adding (insertion or placement) the electronic components to the PCB. A minimum of one operation for each package style and number or leads, pins or pads is required. To make it easier, an average cost for the components covered by each operation is used. These costs are included in the overall material costs for the analysis. If an exact component cost total is critical, then instead it is necessary to use an operation from the library for each individual component added, so that specific component costs can be entered. For this analysis, use the average component costs given in the previous table. 5. Choose Insert Library Operation from the Analysis menu or click to open the Library Operations dialog.

For each insertion or placement operation it is necessary to select the method of insertion or placement (Auto, manual, etc.). This means that components of the same style and number of leads, but inserted or placed by different methods must be covered by separate library operations. All operations for this are located in the Operation Library.

6. In the Printed circuit board assembly category, open the Through hole insertion subcategory. Highlight DIP insertion and click the Add button twice to add two of these operations to the Process Chart. In the same way, add the indicated number of the following operations from the Through hole insertion subcategory: It’s most efficient to add these operations all at once, then adjust the responses as required later.

SIP insertion (3) Radial insertion (1) Can insertion (1) PTH connector insertion (7)

7. Expand the Surface mount placement subcategory and add one Chip placement and one Quad flat pack placement operation. Close the Library Operations dialog.


Chapter 11 / DFM Concurrent Costing User Guide Now that the operations have been added to the Process Chart, we will highlight each one and adjust the default values according to the information on the parts list table. 8. Select the first DIP insertion operation. Change the Number of pins to 20 and the Number of components inserted to 3. After the 3 has been entered a new response for the Number of component types of this package style will appear. The default of 1 should be changed to 2. Enter .10 for the Average component cost .

Highlight each additional PCB assembly operation on the Process Chart and adjust the inputs according to the parts list table. 9. Highlight Can insertion on the Process Chart and select Manual for the Insertion method . Since the can is bonded over for attachment to the outside of the board by hand soldering we will add a hand soldering operation. Open the Library Operations dialog and add the Hand solder operation from the Miscellaneous operations subcategory. 10. Highlight the Quad flat pack placement on the Process Chart and select Robot for the placement method. Also check Replacement component required? to indicate that during any rework a replacement component will be required.


DFM Concurrent Costing User Guide / Chapter 11 11. The Whole board operations are now added from the operations library. With Quad flat pack placement still selected on the Process Chart, add the following operations: Solder paste-manual Reflow solder Wave Solder Cleaning Functional testing In-circuit testing

The default responses can be used for all operations in this case. 12. The final operation to be added is for the addition of the 9 jumper caps to some of the connectors on the board. These should be added before Functional testing in the sequence of processes, although the position in the process chart will not affect the results. Highlight Cleaning on the Process Chart, then select Enter Part from the Analysis menu.

...or on the toobar select

13. In the responses enter jumper cap for the Part name. Change the Repeat count to 9 and Material cost per part to 0.02. 14. With the jumper cap highlighted on the Process Chart, select Insert Operation from the Analysis menu. Open the Assembly category and add Acquire and insert parts to the Process Chart. Close the Library Operations dialog. 15. On the Responses Panel for the operation, accept the default of Non rotational part . Enter dimensions of Part length 0.4 inches, Part Width 0.2 and Part depth 0.1. Change the Repeat count to 9. In the group Orientation of insertion axis select One way and in the group Orientation about insertion axis select Either way. Accept the default of No handling difficulties and in the group Insertion select Part secured immediately for Insertion type. Accept all other defaults.

...or on the toobar select

You have now completed the PCB analysis. You can compare your results with the completed sample file video board.dfm included with your software in the \data\samples subdirectory.






Chapter 12

Develop a user process Introduction The User process program allows you to install into the DFM Concurrent Costing software your own cost model for a manufacturing process. For this tutorial, an imaginary process named “Forming” will be added which has three operations, namely: 1. Preheating the workpiece. 2. Forming the workpiece to the desired shape. 3. Trimming the workpiece to produce the part. Preheating the workpiece is optional and the user can select automatic or manual trimming of the part. Appearance and functionality of the completed Forming process

1. When the user starts the Forming analysis, the usual initial responses are made including the life volume, part envelope shape selection, part overall dimensions, and the direction of forming. 2. The user clicks Select process and material to display the process and material selection dialog. The User processes category available at the bottom of the process listing is opened and the Forming process is selected. The Aluminum alloy material category is opened and Duralumin is selected.

3. The screen for the Forming process is displayed and a default cost estimate for the described part is generated immediately. The default Process chart appears on the left while the Main response panel for the Forming process appears on the right.

As with most Boothroyd Dewhurst cost models, the Main response panel for the Forming process contains all inputs required to complete the analysis of a part.

A user process / 101


4. The user refines the default cost estimate for the part by adjusting inputs on the Main response panel. The user clicks the button alongside the Part volume field to display the Volume geometry calculator, which would be used to define a value for the Part volume field. A similar calculator would also be used to define a value for the Part projected area field.

5. Once the voume is defined, the user selects Transfer and close from the Geometry menu and returns to the Main response panel. Preheating is not required for this Duralumin material so the Preheating required checkbox is unchecked. After Calculate is clicked, the Preheat workpiece operation is automatically removed from the Process chart.

102 / A user process


6. Automatic trimming will be used for this part so the user changes the Type of trimming dropdown to auto trim and clicks Calculate. The trimming operation is automatically changed to an auto trim operation.

7. Analysis of this part is now complete and the results can be presented in the software’s reports and graphs. Add the Forming process and associated operations to the Process library

You can also insert the process by clicking the toolbar button.

1. Open the User Process Library by choosing it from the View menu. 2. Choose Process from the Insert menu. A new user process is added to the library with its name in edit mode. Name the process Forming and press the Enter key to accept the name. 3. Click on the Items not yet added entry beneath the Forming process and select Operation from the Insert menu. A new operation is added with its name in edit mode. Type preheat workpiece and press the Enter key. 4. Insert two more operations under the Preheat workpiece operation. Name them form workpiece and auto trim part

You can also insert the operation by clicking the toolbar button.

All operations that may be carried out during the user process are added in the library even though some may not be required under certain circumstances. The Manual trim part operation will be added to the library later.


Chapter 12 / DFM Concurrent Costing User Guide A material code name can be any text that identifies the material. The name of the material or an ab breviated material name is commonly used. When defining formulas for the process and operations, the material code names on each line are recognized by the program. The code name on the first line will be material code name 1, the code name on the second line will be material code name 2, and so on.

Define materials that are applicable to the Forming process

1. Click on the Forming process to display the Material code names box on the right. 2. Into the Material code names box, type AL1100 and press the Enter key to begin a new line. On the new line, type AL5050 and press the Enter key to begin a third line. On the third line, type Duralumin and do not press the Enter key.

Define the process level formulas 1. Open the process level Formula window by selecting Formula from the Edit menu. 2. Before entering formulas, be sure English is checked in the Variables menu. 3. In the top panel of the window, enter the following expressions.

The Formula window accepts standard copy and paste commands.

Raw_material_cost = 1.25; Raw_material_cost = Material_code_name == 2 ? 1.58 : Raw_material_cost; Raw_material_cost = Material_code_name == 3 ? 2.29 : Raw_material_cost; Material_scrap_value = 0.15; Material_scrap_value = Material_code_name == 2 ? 0.19 : Material_scrap_value; Material_scrap_value = Material_code_name == 3 ? 0.28 : Material_scrap_value; Material_density = 0.097; Material_density = Material_code_name == 2 ? 0.094 : Material_density; Material_density = Material_code_name == 3 ? 0.090 : Material_density; Forming_pressure = 100; Forming_pressure = Material_code_name == 2 ? 150 : Forming_pressure ; Forming_pressure = Material_code_name == 3 ? 200 : Forming_pressure ;


DFM Concurrent Costing User Guide / Chapter 12 Batch_size=Life_volume / 8; Extra_material_factor; Overall_plant_efficiency; Part_weight = Part_volume * Material_density; Part_projected_area; Preheating_required; Type_of_trimming;

Material library data is normally defined using formulas in the Process level formula window.

4. Click Calculate to display the list of variables in the bottom panel of the window.

Define the Main response panel 1. Some variables are to be displayed on the Main response panel. These are listed below. Drag and drop these variables within the variables listing so that they are in the order shown and are at the top of the list. Batch_size Overall_plant_efficiency Raw_material_cost Material_scrap_value Part_volume Part_projected_area Preheating_required Type_of_trimming 2. For all the remaining variables change Always to Never in the Show to user column.

For variables that are shown on the Main response panel, the order in which they are shown is determined by their order within the variables listing.

3. Make the following change for the Part_volume variable. Calculator type - change from None to Volume 4. Make the following change for the Part_projected_area variable. Calculator type - change from None to Projected area 5. Make the following changes for the Preheating_required variable. Type - change Number to Checkbox. Click Yes to the confirm dialog that appears. Value - click the checkbox so an x appears

The Calculator type column provides for use of the geometry calculator in an analysis to calculate a value for a variable.

6. Make the following changes for the Type_of_trimming variable. Type - change Number to List button that appears. In Value - click into the cell and click the the List Contents dialog that is displayed, replace no data by typing Auto and press Enter to start a new line. On the new line type Manual and do not press Enter. Click OK to close the dialog.


Chapter 12 / DFM Concurrent Costing User Guide 7. To complete the variables list, enter the values, units, conversion factors and descriptions shown below.

Superscript numbers can be copied into the units columns using your operating system’s character map which is available by clicking the Windows Start button followed by All programs - Accessories - System tools - Character map. The list of program variables is available by selecting Insert program variable from the Variables menu. All variables defined in the process level formula window, as well as the standard program variables, appear in the program variables list for operations. The Material_weight program variable must be calculated for each operation in a process that will use the hard-coded cost of rejects calculations.


8. Click OK to exit the process level Formula window and return to the Process library. Define the operation formula for the Preheat workpiece operation

1. Double click the Preheat workpiece operation to open the Formula window for that operation. 2. In the top panel of the window, enter the following expressions. Material_weight = Part_weight * Extra_material_factor ; Heating_cost = Material_weight * Heating_cost_per_unit_weight; Process_cost = (Time_to_load_and_unload * Heating_process_rate / 3600 + Heating_cost) /(Overall_plant_efficiency / 100); Setup_cost = Setup_rate*Setup_time/Batch_size; 3. Click Calculate to display the list of variables in the bottom panel of the window.

DFM Concurrent Costing User Guide / Chapter 12 Define the operation response panel for the Preheat workpiece operation

1. Drag and drop the following variables which will be displayed to the user so that they are in the order shown and are at the top of the variables listing. Setup_rate Setup_time Heating_process_rate Time_to_load_and_unload Heating_cost_per_unit_weight 2. For all the remaining variables change Always to Never in the Show to user column. 3. To complete the variables list, enter the values, units, conversion factors and descriptions shown below.

Part_weight and Extra_material_factor are program variables that have had their values defined in the Formula window for the Forming process.

4. Click OK to close the Formula window. Define the operation formula for the Form workpiece operation

1. Double click the Form workpiece operation to open the Formula window for that operation. 2. In the top panel of the window, enter the following expressions. Material_weight = Part_weight * Extra_material_factor; Material_cost = Material_weight * Raw_material_cost; Forming_force = Forming_pressure * Part_projected_area; Time_per_part_for_forming=Part_depth/Forming_force*Forming_ time_constant; Process_cost = ((Time_to_load_and_unload + Time_per_part_for_ forming) * Process_rate_for_forming) / 3600 / (Overall_plant_efficiency / 100); Tooling_cost_per_part=Initial_tooling_investment/Life_volume;



3. Click Calculate to display the list of variables in the bottom panel of the window. The Time_to_load_and_ unload variable in this operation is independent from the Time_to_load_ and_unload variable in the Preheat workpiece operation. All program variables are either hardcoded or come from the process-level formula window.

Define the operation response panel for the Form workpiece operation

1. Drag and drop the following variables which will be displayed to the user so that they are in the order shown and are at the top of the variables listing. Process_rate_for_forming Time_to_load_and_unload Time_per_part_for_forming Initial_tooling_investment 2. For all the remaining variables change Always to Never in the Show to user column. 3. To complete the variables list, enter the values, units, conversion factors and descriptions shown below.

4. Click OK to close the Formula window.


DFM Concurrent Costing User Guide / Chapter 12 Define the operation formula for the Auto trim part operation

1. Double click the auto trim operation to open the Formula window for that operation. 2. In the top panel of the window, enter the following expressions. Material_weight = Part_weight; Process_cost = Auto_trim_time * Process_rate_for_trim / 3600 / (Overall_plant_efficiency / 100); 3. Click Calculate to display the list of variables in the bottom panel of the window. Define the operation response panel for the Auto trim part operation

1. Drag and drop the following variables which will be displayed to the user within the variables listing in the bottom panel of the Formula window so that they are in the order shown at the top of the list. Process_rate_for_trim Auto_trim_time 2. For all the remaining variables change Always to Never in the Show to user column. 3. To complete the variables list, enter the values, units, conversion factors and descriptions shown below.

4. Click OK to close the Formula window. Define the manual trim part operation

1. Copy the auto trim part operation by selecting Copy from the Edit menu. Paste the operation by selecting Paste from the Edit menu. 2. Rename the second auto trim operation to manual trim part by right clicking the operation and selecting Rename.


Chapter 12 / DFM Concurrent Costing User Guide Define the operation formula and response panel for the Manual trim part operation

1. Double click the manual trim operation to open the Formula window for that operation. 2. Change the Value column for the Trim_process_rate variable from 50 to 30. 3. Change the Value column for the Trim_time variable from 4 to 6. 4. Click OK to close the Formula window Define display conditions and reject rate defaults for operations

1. Click on the Preheat workpiece operation beneath the Forming process and select Sometimes from the Display operation dropdown. 2. Click the

button near the Condition field.

3. During an analysis, the preheat workpiece operation will be displayed on the Process chart whenever the Preheating_required checkbox is checked on the Main response panel. For this reason, highlight Preheating_required on the left and type 1 into the Value field on the right.

Checkbox variables have a value of 1 when checked and a value of 0 when unchecked List variables have a value equal to the line number of the selected entry on the list.

Changes made to the li brary are saved automatically upon exit.

4. Click OK and highlight the auto-trim operation. Click the Display reject field checkbox that appears on the right. Enter 0.5 into the Default value for rejects field. 5. Select Sometimes from the Display operation dropdown and click the button near the Condition field. 6. During an analysis, the auto trim operation will be displayed on the Process chart whenever auto trim is selected from the Type_of_ trimming list on the Main response panel. For this reason, highlight Type_of_trimming on the left and type 1 into the Value field on the right. Click OK to exit the display conditions window. 7. Highlight the manual trim operation and perform the same steps except enter 2 into the Value field when defining the display conditions. 8. Close the Process library by choosing Exit from the File menu.



Link the material library with the Forming process 1. From the main window of DFM Concurrent Costing, choose Material library from the View menu. 2. Expand the Aluminum alloy category by clicking the alongside that category.

button

3. Highlight the AL1100 aluminum, annealed material and click the Forming checkbox that appears on the right. 4. Click the Forming entry that appears beneath the AL1100 aluminum, annealed material and choose AL1100 from the Material code name dropdown on the right. 5. Highlight the AL5050 aluminum, annealed material and click the Forming checkbox that appears on the right. Click the Forming entry that appears beneath the material and choose AL5050 from the Material code name dropdown on the right. 6. Highlight the AL7075 aluminum, heat treated (T6) material. Choose Material from the Insert menu and a new material is added to the library with its name in edit mode. Name the material Duralumin and press the Enter key to accept the name. 7. Click the Forming checkbox on the right and highlight the Forming entry that appears beneath the material. Choose Duralumin from the Material code name dropdown on the right.

Adding a process to the Process library automatically adds a corresponding checkbox to all materials in the material library.

When the AL1100 aluminum, annealed material is chosen during an analysis, the AL1100 material code name will be used in the Forming process calculations.

8. Close the Material library by choosing Exit from the File menu.


Chapter 12 / DFM Concurrent Costing User Guide Removing the imaginary Forming process

1. The Forming process added during this tutorial is completely imaginary and should not be used to analyze real formed parts. For this reason, the Forming process should be removed from the Process library after the process is created. Open the Process library by choosing it from the View menu on the main screen of the software. 2. Highlight the Forming process and select Delete from the Edit menu. Click OK in the Confirm dialog that appears. 3. Close the Process library by choosing Exit from the File menu. 4. Open the Material library by choosing it from the View menu. 5. Expand the Aluminum alloy material category and highlight the Duralumin material. Select Delete from the Edit menu and click OK in the Confirm dialog that appears. 6. Close the Material library by choosing Exit from the File menu.



Chapter 13

The Material Library The Material Library contains data for process/material combinations grouped within material categories. You can add your own categories and you can add materials within categories. For each material there is a list of suitable processes with data for each of the processes. 1. Open the Material Library by choosing it from the View menu. 2. If necessary, expand the material category Carbon steel by clicking next to the category name. Note the list of materials within the category. 3. Expand the material name Generic low carbon steel by clicking the . Observe the check boxes on the right window panel, indicating which processes are suitable for the material. This information is used to filter your selection of process and material combinations for a cost analysis.

The means that the node on the chart tree is already expanded. The materials in the library are those available in the Process and material selection dialog.

4. Click the Investment casting entry under Generic low carbon steel. The values on the right panel are used in estimating the cost of an investment casting using low carbon steel.

The Material Library / 113


5. The section Practical Limits Data gives the approximate manufacturing limits for the material and process. If your initial part definitions for an analysis exceed any of the limits defined in this section, you will get a warning as you complete your process and material selection. However, you will be able to complete your analysis with the selected material.

Machining material data 1. Highlight Machining under Generic low carbon steel , and enlarge or maximize the library window to see all the variables on the right window panel. 2. Machining material data consists of basic material properties and cost data, operation and cutting tool selections and cutting speed and feed data. It also provides empirical indices correcting speeds and feeds for different hardness values and different depths of cut or tool diameter. 3. In the Machining operations data box, click the Drilling operation name in the left-hand box. Note that the Tool list, on the right side panel in the image on the next page, changes depending on the characteristics of the machining operation.

114 / The Material Library


4. The machining variables for drilling with a high-speed steel tool are shown beneath the selection boxes. The variables depend on the operation. 5. When you add a machining operation to an analysis, generally there is a list box response for Tool material . Most machining operations have a tool material selection list box. If there is cutting data for an operation/cutting tool combination, the tool material will be included as a choice. 6. In the drilling operation selection shown above, the default choice for tool material when the operation is added to an analysis is High-speed steel . If you would rather make Carbide the default choice, you can move it to the top of the list by clicking the up arrow beneath the Tool box.

If you select Diamond or CBN from the tool list, you will see that the cutting speed and feed fields are blank. There is no cutting data available. Therefore it will not ap pear in the Tool material list box when drilling is added to an analysis.



Sheet metalworking material data To see more variables, use the vertical scroll bar or maximize the window.

1. Now move to the left panel on the window, and highlight the Sheet metalworking process for Generic low carbon steel. 2. A different set of variables is shown on the right panel for this process.

3. Sheet metalworking material data consists of basic material data, stock forms in costs per unit weight by thickness; and other data needed for the sheet metal processes, including Laser and Plasma cutting. Practical limitations boxes appear at the end of the variables. 4. You can add to or change the stock data. To add a standard sheet size to the Standard sheet sizes box, select the row you want the new material to appear above. Then click the Add button on the right side of the group box. A new row is added. You would then supply the length and width data. 5. To delete the row, select it by clicking in the number row. Then click the Delete button on the right side of the group box.



Adding a new material 1. In the category Carbon steel , click the last material name in the category ( Medium carbon steel, hot rolled ) and choose Material from the Insert menu. An edit box is added under the last material. 2. Type New carbon steel in the material name box, and press Enter. Note that the upper right panel displays a list of the processes currently available in the software.

You can have more than one Material Library. To change the library a DFM analysis is accessing, change the default library in the Librarian dialog. The toolbar button for adding a material entry is

3. When you check Sand casting in the list of processes, it appears as a process available for the new material. 4. Now check the investment casting and hot forging process boxes; observe the processes added to the list below the material name.

5. When you add data for a process/material combination it is usually helpful to copy and paste the data from a similar material and then edit the data where necessary. 6. Open the Generic low carbon steel material if necessary, click Sand casting and choose Copy from the Edit menu.

Determine the insertion point in the chart by highlighting an entry. The Insert command adds the new entry below it. ...or from the toolbar choose

7. Click the Sand casting process for New carbon steel and choose Paste from the Edit menu. Click Yes in the warning dialog about replacing data. 8. Observe that the data for Sand casting has been copied into the new material and can now be edited.

...or from the toolbar choose



9. Click New carbon steel and choose Delete from the Edit menu. Confirm that you wish to delete the entire record. Move a material or category on the chart by cut and paste; or drag and drop with the mouse. Moving and copying in the Material Library chart can be slow depending on processor speed.

10. Rather than copying and pasting data for each process, you can copy and paste the entire record for a material. 11. Click the material Generic low carbon steel. Choose Copy from the Edit menu. 12. Click the name of the last material in the Carbon steel category and choose Paste from the Edit menu. Click the newly pasted material once to rename it. 13. Type New carbon steel. Press the Enter key. Note that all the ap propriate processes have been checked.

14. Expand the new material if necessary and then select the various processes to display the data ready for editing. ...or from the toolbar choose

15. Choose Delete from the Edit menu to delete the new material and close the library.



Chapter 14

The Machine Library The Machine Library contains categories and machine data needed when machines are specified in the machine setup entry. In this chapter we view an existing machine entry in the Library, add a new machine, and review automatic and manual selection of machines. The Machine Selection Profile dialog is shown.

The machine data 1. From the main window of DFM Concurrent Costing, choose Machine Library from the View menu. 2. The machine categories are on the left panel, and the right panel is blank until a machine entry is clicked. Scroll down to the Stamping presses category. Click the handle to show the presses. Click the Minster OBI #5F (45 Ton) machine. 3. The window now has the data associated with this machine in view on the right panel. The top box is Machine identification. Fields in this section determine the type of machine and with which process the machine is to be used. Subsequent sections apply press characteristics, dimensions and other data needed in the process calculations.

Some processes use machine rates based on part characteristics. In those cases, there is no entry for a machine setup on the Process Chart and estimated rates can be edited in the analysis responses if necessary.

These fields can be edited in the library; they are also presented during an analysis, so that analysisspecific changes can be made without affecting the defaults stored in the library.

The Machine Library / 119

Chapter 14 / DFM Concurrent Costing User Guide 4. In addition to the editable fields there is a Comment box and Picture box. Text placed in the Comment box is available in the analysis. The same is true for the picture box. To view a picture of a lathe, open the Lathe category in the Machine Library chart. Click the Tsugami BS12C-III CNC Swissturn. Scroll down, if necessary, to see the following:

The machine tool categories in the Machine Library are: Boring and drilling Broaching Gear cutting Grinding Lathes Machining centers Milling machines

Another condition needed to add a machining operation to an analysis is that the material variables (stored in the Material Library) of the part being machined contain the data needed in the machining operation calculations.

5. With the lathe entry open, note that the fields are different for this machine category. For the machine tool categories, there are checkboxes for the operation types that can be carried out. Scroll down to view the Main operations and Live tools operations boxes. Whether an operation is checked for a particular machine tool determines, in part, whether the operation appears in the Library Operations dialog when you are adding machining operations to a setup.

120 / The Machine Library


Adding a new machine One way to add a machine to the Machine Library is by copying an existing, similar machine entry. 1. On the Machine Library chart, click the Laser cutting category handle to open it. Highlight the Cincinnati CL-7A Laser System. 2. Choose Copy from the Edit menu; and then Paste. A copy of the laser machine is placed beneath the existing one. 3. Click the copied machine name on the library chart to put the name into edit mode, and type New laser machine. Press the Enter key.

4. All the data has been copied from the existing machine. You can now adjust the data as needed to reflect the specifications of the machine you are adding. 5. Alternatively, you can add a machine and supply all the data for all fields. Click the handle of the Plastic injection molding machines category to show its entries. Click the last entry in the list.


6. Choose Machine from the Insert menu. A new entry is added beneath the HPM Corporation H2000 machine entry. Type New injection molding machine . 7. Before supplying data for the fields for your new entry, you must set the Machine identification fields on the right panel. In the Process application field, drop the list down and choose Plastic injection molding . 8. For Machine type, there is only one choice, Injection molding machine.

9. As you can see, the fields on the right panel have either blanks or zeros. You would now supply values for all fields. 10. Before closing the library, delete both the machine entries that we have added in this tutorial. ( Edit menu Delete.) →



Automatic selection and the machine library The machines in the library are used by the software in calculating costs in two modes: automatic selection or manual selection. The default is automatic selection; you can see if this is checked in the first response for the setup in an analysis. 1. Open the sample file injection molded part.dfm, a plastic injection molded box cover. 2. Click the setup entry, the Cincinnati Milacron VH500. On the Responses panel, notice that the top section is Machine selection.

3. When the Automatic selection? box is checked, the smallest machine capable of processing the part, at the lowest rate, is automatically selected. This occurs after process/material selection or whenever you click the Calculate button. ... or right-click on the machine in the Process Chart for a menu from which you can choose Change machine.

4. To change the machine setup, highlight the Cincinnati Milacron VH500 setup on the Process Chart, and choose Change Machine from the Analysis menu. 5. You are presented with a Change Machine dialog. Expand the Plastic injection molding machines category, click the Battenfeld BA-T 12500/6300 machine, and then click the OK button.

6. The Battenfeld replaces the VH500 on the Process Chart. There is an adjustment to the processing cost in the Cost results box.


DFM Concurrent Costing User Guide / Chapter 14 7. To return the analysis to its previous results, check the checkbox for Automatic selection and click the Calculate button. The setup is now the VH500 again.

Creating a machine selection profile This feature lets you control which machines are available during an analysis when automatic machine selection is turned on. You can have more than one profile, and you can switch between profiles. The default profile is All machines, in which all categories in the Machine Library are used. 1. With the injection molded part.dfm still open, choose Machine Selection Profile from the Analysis menu. In the submenu choose Customize... 2. The Machine Selection Profiles dialog opens. This is the default profile, All machines; in an analysis, the software will select the machine from the entire library.

The profiles available from the menu will be those that include the process used in the analysis.



Because machine tool setups cannot be included in a profile, you will have to manually select a specific machine tool, or series of machine tools, if your part includes secondary machining and you want the profile conditions to apply.

3. To create a machine profile, you must first set up one or more categories in the default library that contain the machines you want available in the profile. You can make categories for each type of machine or all your preferred machines can be placed in the same category. In both cases, for each machine, the correct process application and machine type must be specified in the Machine identification box on the right panel. 4. The processes available to be profiled are those in the dialog. 5. To add a new profile, click the Add button, name your profile, and make the appropriate selections in the dialog. Click the OK button to return to the main window with your new profile now the default selection. 6. To switch to a different profile, choose Machine Selection Profile from the Analysis menu, and click the profile you want from the submenu. You might choose to use these profiles in developing cost estimates when significant rate differences exist depending on the location of the manufacturing site; or when there are certain setups typically available for part production.



Chapter 15

The Operation Library The Operation Library includes several kinds of operations, including all machining operations, all assembly fabrication and welding operations, all automatic assembly operations and miscellaneous other operations that commonly occur in manufacturing and contribute to part cost. These operations are added to analyses, and their results are included in overall totalling of costs. The library is user editable; it consists of a tree chart to organize the library, and a formula window where the expressions and variable definitions are set out. The formulas are written in a simple structured language that includes conditional expressions. For each variable within a formula, you have control over when and how it appears as a response in an analysis and can specify for the conversion of units.

Add a new operation In this tutorial we add a special machine loading operation where the time taken is 2 seconds for every pound of part weight. However, when the part weighs less than 5 pounds, the time is constant at 10 seconds and when the part weighs more than 30 pounds, a hand crane is used and the time again becomes independent of part weight. The cost per part for this operation is calculated from the time and the specified labor rate for loading. The expressions necessary to describe the process cost per part can be written as follows: Loading_time = Part_weight * 2 ; Loading_time = Part_weight < 5 ? 10 : Loading_time ; (this expression states that if the part weight is less than 5, the loading time equals 10; otherwise it retains the value given by the first expression)

You can determine where a category or operation is inserted by highlighting the entry on the chart that you want the new entry to go after. Add category button

Loading_time = Part_weight > 30 ? 60 : Loading_time ; (similarly if the part weight is greater than 30 the loading time equals 60; otherwise it is unchanged) Add operation button:

Process_cost = Labor_rate * Loading_time / 3600 ; 1. Open the Operation Library by choosing it from the View menu in the DFM Concurrent Costing main window. 2. Choose Category from the Insert menu. A new category and indented Items not yet added entry are inserted beneath the previously highlighted entry. The category name is in edit mode. Type Special machine operations . Press the Enter key to accept the name.

The Operation Library / 125

Chapter 15 / DFM Concurrent Costing User Guide 3. Highlight the Items not yet added entry. Choose Operation from the Insert menu. The operation name is in edit mode; type Machine loading and press the Enter key. Machining operations use a different set of program variables, and varying material library data. Therefore it is necessary to specify whether or not the operation is a machining operation, and if it is, what kind.

4. With the new operation highlighted, note that there is a Type of operation box on the right panel of the window. The default choice is Generic, which is used for all operations except machining, assembly fabrication, automatic assembly and printed circuit board operations. 5. Check the Display reject field to make the Rejects, % response available for editing when our operation is used in an analysis. 6. Enter 1 in the box Default value for rejects. This is the percent value that will appear in the Responses. It will be editable.

Program variables get their values from calculations in the software. In the formula table, you may make a program variable user editable. If this value is shown to the user and edited, it will be locked and not receive its value from the software calculation. You cannot add to the Program Variables list. If you have your own variables that you frequently use in developing formulas, you can include them in the User Variables list. (In the formula window, choose it from the Variables menu.)

7. Double-click the name of the operation you just added to go to the Formulas window. 8. Before making entries, see that English is selected in the Variables menu.

9. We are going to enter the expressions from the previous page in the top panel of the window. The first expression contains the variable Part_weight. Because it is a program variable, you should copy it from the Program Variables dialog as follows: 10. Type Loading_time = (Note that formula variables need the underscore character instead of spaces.)

A full explanation of formatting and syntax for the formulas is available in On-line Help. On the index tab of the Help window look up ‘Formula syntax’.

11. From the Variables menu choose Insert Program Variable to open the Program Variables table. Scroll the list and select Part_weight by clicking its name. Click the Copy to Formula button. The variable name is added to the expression. Move the Program Variables window out of the way. Type: *2;

126 / The Operation Library

DFM Concurrent Costing User Guide / Chapter 15 Note that you can space and skip lines, except within a variable name. 12. Continue to enter the expressions as below, inserting Part_weight on the next two lines, and Process_cost on the last line from the Program Variables window.

Note in the completed formula that each line ends in a semicolon. This is required syntax. 13. Click the Calculate button to display the list of variables. The rows for program variables Part weight and Process cost are completed and the Process_cost name appears bold to indicate it is included in the Cost results box when the operation is added to an analysis.

14. Enter 10 in the Value column for the part weight. 15. For the Loading_time variable, leave the defaults, except for the following:

• Responses Panel Label , Time to load one part • User can edit? unchecked • English and metric units, s; s • Description,time to load the special machine 16. For the Labor_rate variable, leave the defaults, except for the following:

• English value, 30 • Number of Decimals, 0 • English and metric units, $/hr; $/hr

You can move the splitter between the formula pane and the table to resize each as needed. You can also stretch and shrink the window.

The software will indicate syntax errors. After entering expressions, click the Calculate button. The cursor will be placed at the first error point in the formula pane; and the hint bar will describe the type of error.

Change the order of the variables by dragging and dropping the No. column for the variable row. This is the order the variables will appear on the Responses panel when the operation is added to an analysis. Right-click on the No. column and select Insert Group Title to separate variables into groups. A title will appear above the selected row. Once added to an analysis the operation’s variables will be arranged in group boxes designated by these title rows.

The Operation Library / 127

Chapter 15 / DFM Concurrent Costing User Guide The columns on the table can be resized. Click the heading column, and then pass the pointer over the line between panes. When it becomes a double-arrow, you can drag the edge. The Responses Panel Label field allows you to have a text label in the operation Responses that is different from the variable name. Specify the variables you want displayed in the Responses (Show to user?) and whether you want them to be editable by the user (User can edit ?) ?)

• Conversion factor , 1 • Description, cost per unit time for the worker and equipment.

17. Since the purpose of the Process_cos Process_cost t variable is to include this cost in the results for the analysis, you would not normally make it user editable. You need not show it to the user, since it is already present in the Cost results box. Choose Never in the Show to User column. 18. Click the Calculate button. Note that the loading loading time is 20 seconds and the process cost is $0.1667.

You can try other values of the part weight to test the expressions. 19. Close the Program Variables Variables window and click OK to exit the Formulas window w indow.. 20. In the Comment pane for the Machine loading operation, type a description of it, as below. (Text (Text available from another source can be pasted into the Comment field.)

21. You You can also insert i nsert ( Load ) a picture related to the operation if available. The Picture and Comment boxes are included in the Responses when the operation is added to an analysis. 22. Now we will add this operation to an analysis. Close the Operation Library and open the sample file hot forged part.dfm included with your installation of DFM Concurrent Costing ( \data\samples.) 23. Highlight the inspection operation so that our machine loading operation will be added below it. Right-click in the Process Chart, and choose Insert Operation. In the Library Operations dialog, click the handle for the Special machine operations category.

128 12 8 / Th Thee Op Oper erat atio ion n Li Libr brar aryy

DFM Concurrent Costing User User Guide / Chapter 15 24. Double-click your new operation Machine loading . It is added to the Process Chart. Click the Calculate button to update the Cost results under the Process Chart.

25. Now choose Revert to Saved from the File menu to return the hot forged part file to its state before adding the operation. 26. Open the Operation Library, and delete the category Special machine operations by choosing Delete from the Edit menu.


27. Close the Operation Library window.

Changing the default library When a library operation is inserted into an analysis, the software uses the default Operation Library. If you have multiple libraries for any of the DFM libraries, you can control which one the software is currently accessing through this dialog. 1. To tell the software to use a different library, library, choose Librarian from the Tools menu on the main window window.. 2. The dialog specifies the current default libraries.

The Library Operations dialog shows operations that can be added to the current analysis. Machining operations are not available except when they are to be added to a Machine Tool setup already on the Process Chart.

The Operation Operation Library / 129


If you have accessed the library file before, you can switch to it by clicking the list box down arrow in the library name field and selecting it.

3. If other libraries are available, you can select a different one by clicking the Browse button. 4. In the Locate dialog which opens when you click the Browse button, find the path to the file in the Look in list box field. Then you would select the library file and click the Open button. For this exercise click the Cancel button. 5. The default library is changed changed until you change it again in the Librarian dialog. Close the dialog by clicking the Cancel button.

130 13 0 / Th Thee Op Oper erat atio ion n Li Libr brar aryy

Index A Add analysis to file 30 category 113,125 geometry shape 34 library operation 8,71 machine tool 7,15 machine tool setup 15,42 machine to library 121 machining operation 16,43 new material 117 operation to analysis 15,128 operation to library 126 picture 128 stock data for sheet metalworking 116 Additional setups 22,29,60 Analysis copy 28 Appearance 12 Approximate envelope dimensions 33 envelope dimensions and machining 40,70 estimate 10 Area buttons geometry calculator toolbar 25 Assembly fabrication 8,69 Assembly labor rate 71 Automatic machine selection 13,27,122 Automatic Assembly 77 Average thickness 6,9

B Bend button sheet metal geometry calculator 25 Blue field color 10 Break-even point 31

C CAD data 6 importing 11

Calculate button 11,12,16,127 cost results pane 7,30 formulas window 128 Category material library 113 operation library 125 Cavities number of 12 Change machine dialog 122 material or process 28 Chart geometry calculator 34 geometry tabs 34 hide entries 10 process 5,10 reveal entries 10 Chart tab 61 Close window 37 Cold-chamber die casting 17 Color material and process selection 10 Column resize formulas window 128 Combine operations 63 Comment pane 128 machine library 120 Compare analyses 8,17,30,44,65 Compound die stamping 65 Copy analysis 17,28 material 117 Cost reduction guide 20 results 5,9,11,18,30,71 versus life volume 19,30,44 Cost breakdown bar graph 20 stacked bar graph 20 table 20 Current column in results 44 Custom punches 25 Cutting material data machining 115 Cut from stock 39,47

Index / 131

Cycle time 14

G

D

Geometry calculator 11,23,49,61 calculator and CAD 6 entering directly in responses 30 Graphs 19,44 Green indicator process and material selection 10,22 Group Title 127

Delete material from library 118 operation from library 129 sheet metal stock form data 116 Density, material and part weight 11 Die casting cold-chamber 17 hot-chamber 9 Die data 12 Dimensions approximate 9 machining 16 Direction die closing 36 Dock library 43,71 Drag and drop moves 118,128 Drilling material data 114

E Edited response 10 English dimension units 9 Envelope shape 9 Estimate approximate cost 22 Expand entry on chart 113

F Fabricated assembly 8,69 Features tab geometry calculator 24 File open 19 Flattened dimensions 22 Forming direction 9 Formula pane resize 127 Formula window 126 Form features sheet metal geometry calculator 25

132 / Index

H Hardness, material 18 Help, on-line 12,126 for machining operations 43 index 11 Hint bar 12 Hits number of in turret calculator 24 Holes in sheet metal calculator 25 Hot-chamber die casting 9

I Import DFM analysis 30 Insert material 117 operation 125,126 program variable 126 Insertion point process chart 125 Irregular hole sheet metal geometry calculator 25

L Labor rate assembly 71 Laser cutting data material library 116 Librarian dialog 129 Libraries in DFM software 8 Library default 117,129 machine 119 material 113 operation 125

Library operations dialog 8,16,43,71 Life volume 9,19 Limits practical 22 Limits practical 10 Live tool operations 120 Lock field 10,37

responses 13 order of 127 Operation time machining 44 Orange indicator process and material selection 10 Outer perimeter 11

M

P

Machine automatic selection 122 identification 119,121 library 13,119 selection profile 123 selection profile and machine tools 124 setup 15 tool categories 120 tool setup 7 Machined/cut from stock 39,47 Machining 7 adding an operation 43 conditions for adding operation 16,120 material data 114 operation types in machine library 120 picture of operation 43 quick estimate 47 Material cost per part 26 library 10,22,113 Material/process selection 10,113 Material form stock 40

Page setup 31 Part description panel 6 number 9 Parts per sheet 22 Paste in material library 117 PCB assembly steps 93 Perimeter geometry calculator 35 Picture adding to an operation 128 add for any chart level 19 box for chart entry 17 float picture box 75 in machine library 120 machining operation 17,43 Plasma cutting data material library 116 Practical limits data 10,114 Previous column 18 cost results 7,44 Printed Circuit Board Assembly 93 – 100 Print preview 31 Process chart 5,10 chart tab 17 cost in operation library 127 list in material library 117 setup not specified 15,119 Process/material selection 10,113 Processing direction sheet metalworking 29 Program variable 126 Projected area 11 geometry calculator 35 Punches

N Name geometry entry 34 Near net shape machining 39 Number, part 9

O Open file 19,33 geometry calculator 34 Operation library 8,125

Index / 133

custom 25

Q Quick estimate 47

R Red indicator process and material selection 10 Rejects 13 Reload library data 13 Repeat count 35 Report graph 31 totals comparison 20 Resize window pane 128 Responses automatic generation 60 material library 117,118 panel 10 panel label in operation 128 part geometry 33 Results compare 18,30 geometry calculator 36 pane 5,127 Revert to saved command 38 Roll up on chart 113

S Sample analysis casting comparison.dfm 19 deep drawn part.dfm 59 geometry calculator.dfm 33 hot forged part.dfm 128 injection molded part.dfm 122 machined or cast part.dfm 39,44 sheet metal stamped part.dfm 21 welded assembly.dfm 72 Save file 15 revert to saved 129 Scrap rate 26 Select material 10,17 process 10,17

134 / Index

Separate button 64 Setup in sheet metalworking 27 Setup/load/unload operation 15 Set units 9 Shape envelope 9 negative 36 Sheet metalworking material data 116 Sheet size 22 Show to user operation variable 128 Side pulls 12 Solid model data importing 11 Special tooling cost machining 44 Surface patches 11 Syntax errors 127 operation formulas 127

T Tabs geometry calculator 34 process chart 17,40 Through hole 11 area 33 group 36 perimeter 33 Tip 9 Tolerance 12 Toolbar geometry calculator 23,61 perimeter in sheet metal calculator 24 Tooling cost special in machining 44 Tool material data in material library 114 default in machining operation 115 selection 43 Tool wear cost machining 43 Total cycle time machining 42

d Fm Cost User Guide

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