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A STUDY ON EQUIPMENT MAINTENANCE AND MANAGEMENT IN LARGE CONSTRUCTION COMPANIES
By V.SUBBURAJ. (Reg No.15204013)
A PROJECT REPORT Submitted to the Department of Civil Engineering in the FACULTY OF ENGINEERING AND TECHNOLOGY
In partial fulfillment of the requirements for the award of the degree d egree Of MASTER OF TECHNOLOGY IN CONSTRUCTION ENGINEERING AND MANAGEMENT
S.R.M ENGINEERING COLLEGE S.R.M. INSTITUTE OF SCIENCE AND TECHNOLOGY Deemed University
May 2006
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BONAFIDE CERTIFICATE
Certified that this project report titled A STUDY ON EQUIPMENT MAINTENANCE
AND
MANAGEMENT
IN
LARGE
CONSTRUCTION
COMPANIES is the bonafide work of Mr. V.SUBBURAJ. who carried out the research under my supervision. Certified further, that to the best of my knowledge the work reported herein does not form part of any other project report or dissertation on the basis of which a degree or award was conferred on earlier occasion on this or any other candidate.
Signature of the Guide ( Mrs.G.Sathyavathy.) Assistant Professor
Signature of the H.O.D ( Dr.M.Lakshmipathy.)
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CHAPTER I
INTRODUCTION
1.1
IMPORTANCE OF EQUIPMENTS
With the advent of heavy construction equipment and the approach of large construction company of converting the construction sector to a more mechanized and in turn an organized sector has made it mandatory for maintaining the fleet of equipments to perform to its optimum.
Since machinery and equipment which have become an integral part of any construction activity and plants and machinery now constitute a substantial portion of the construction cost in a project (in tune of 10 to 30 percent of total project cost depending upon the extent of mechanization), has to be maintained to turn the project into a profit making center for any organization. And also because the cost of maintenance of any equipment is in tune of 200 to 250 percent of cost of equipment it has become imperative for going in for maintaining the equipment during its expected life cycle.
Equipment maintenance is a science because it involves scientific and technical know how of different machineries involved, and it is an art because for identical problem it may require different treatment or action or process. We need equipments for
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technical and speedy construction and at the same time for economical and timely completion of project.
1.2
OBJECTIVE
The objective of this thesis is (i) To study the various maintenance management practices that are currently being employed by large construction sector. (ii) To identify the best practices for effective maintenance management. This study will help to understand the maintenance phenomenon and factors responsible for better efficiency and less operating cost of owning and operating by reducing the downtime of equipment. In addition to the above mentioned objective the study will specifically aim at following aspects.
− Maintenance budget allocation system, − Using software package, Creating a database for carrying out preventive maintenance as per schedule, as well as for maintaining daily status report of equipment deployed at site.
− Quality and safety in maintenance, − Study of management of spare parts and inventory control, − Identifying the best practices of maintenance for the Indian scenario.
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1.3
NATURE AND SCOPE OF STUDY
There are mainly four types of maintenance
− Reactive maintenance / Breakdown maintenance / Corrective maintenance. (Failure Based Maintenance)
− Predictive maintenance and Reliability centered maintenance. (Condition Based Maintenance)
− Preventive maintenance/ Scheduled maintenance. (Time Based maintenance) − Proactive maintenance(Advanced Maintenance technique) 1.3.1
Reactive maintenance
Reactive maintenance is basically the "run it till it breaks" maintenance mode. No actions or efforts are taken to maintain the equipment as the designer originally intended, either to prevent failure or to ensure that the designed life of the equipment is reached. Reactive maintenance is still the predominant mode of maintenance in the Indian construction scenario.
The break down of the maintenance program as followed in India:
a) 67 percent Reactive
b) 31 percent Preventive
c) 2 percent Predictive
The advantages are
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− Has lower initial costs − Requires fewer staff The disadvantages are
− Increases costs due to unplanned downtime of equipment − Increases labor costs, especially if overtime is needed for untimely repairs or replacement
− May increase costs associated with repair or replacement of equipment − May result in possible secondary equipment or process damage from equipment failures
− Is an inefficient use of staff resources. 1.3.2
Predictive Maintenance
A predictive maintenance approach strives to detect the onset of equipment degradation and to address the problems as they are identified. This allows casual stressors to be eliminated or controlled, prior to any significant deterioration in the physical state of the component or equipment. This leads to both current and future functional capabilities. Predictive maintenance techniques provide data that define required servicing and inspection periods so that maintenance departments can determine in advance when equipment must be shutdown for overhaul. Statistics are proving that these programs, when properly implemented, can minimize equipment and system breakdowns, resulting in a major reduction in total maintenance and operating costs.
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Six major diagnostic tools in predictive-maintenance program on a regularly scheduled basis.
− Oil and Wear Particle Analysis − Vibration Analysis − Infrared Thermography − Electrical Testing − Ultrasonic/Acoustic − Process Variables/Inspections/Non-Destructive The advantages are
− Provides increased component operational life and availability − Allows for preemptive corrective actions − Results in decrease in equipment and/or process downtime − Lowers costs for parts and labor − Provides better product quality − Improves worker and environmental safety − Raises worker morale − Increases energy savings
The disadvantages are
− Increases investment in diagnostic equipment
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− Increases investment in staff training − Savings potential is readily seen by management 1.2.3
Preventive Maintenance
Preventive maintenance refers to a series of actions that are performed on either a time-based schedule or a schedule based on that of machine-run time. These actions are designed to detect, preclude, or mitigate degradation of a system (or its components). The goal of a preventive maintenance approach is to minimize system and component degradation and thus sustain or extend the useful life of the equipment. Basic activities involved in preventive maintenance
− Periodic inspection of equipment to uncover conditions leading to production breakdowns or harmful depreciation.
− Upkeep of equipment to minimise downtime and breakdown conditions while they are still in a major stage.
Preventive Maintenance Technologies Applications
− Lubricating − Cleaning − Replacement − Inspecting The advantages are
− Is cost effective in many capital intensive processes and equipment
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− Provides flexibility for the adjustment of maintenance periodicity − Increases component life cycle − Generates energy savings − Reduces equipment and/or process failures − Results in an estimated 12percent to 18percent cost savings over that found in a reactive maintenance program
The disadvantages are
− Does not eliminate catastrophic failures − Is more labor intensive 1.2.4
Proactive Maintenance While predictive maintenance uses online condition monitoring to help
predict when a failure will occur, it doesn't always identify the root cause of the failure. That's where proactive maintenance comes in. Proactive maintenance relies on information provided by predictive methods to identify problems and isolate the source of the failure.
According to major industries throughout the world, it’s time to throw out your old ideas on machine maintenance. The cost-saving trend is toward a maintenance program that targets the root causes of machine wear and failure. Because proactive maintenance methods are currently saving industries of all sizes thousands, of rupees on machine maintenance every year. In many companies it often exceeds annual net profit
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1.3
TOOL FOR THE STUDY
1.3.1
Questionnaire
A questionnaire shall be prepared for collecting data from site regarding maintenance of existing equipment, Inspection record ( i.e. daily/weekly/monthly), repair cost incurred, inventory and spares maintenance, basic infrastructure needed, safety measures adopted etc.
1.3.2
Software package
MS (Access) will be employed for creating a database for carrying out preventive maintenance as per schedule as well as for maintaining daily status report of equipment deployed at site.
1.4
METHODOLOGY
Step 1: Study literature available in the form of books, journals, periodicals, magazines and equipment maintenance manuals of various manufacturing companies to get to proper understanding of the issue.
Step 2: List out various books required for reference and related to topic, collect literature and carry out desk research.
Step 3: Study the maintenance manuals provided by various manufacturers.
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Step 4: Conducting interviews with the concerned personnel.
Step 5: Visit site for data collection and details of maintenance methodology adopted in actual.
Step 6: Analyse the data collected at site and compare it with the standard procedure of maintenance.
Step 7: Identifying the best practices and recommend a model for effective equipment maintenance management.
1.5
LIMITATIONS OF THIS STUDY
The main limitations and constraints for this research study are the paucity of the time and crunch of finance/fund. So, the research is restricted to limited number of case studies. Of course the study has all the limitations of the sampling method and the weaknesses of analytical tools used for the analysis of data collected.
CHAPTER 2
EQUIPMENT MANAGEMENT IN CONSTRUCTION INDUSTRY
2.1
INTRODUCTION
Equipments are main assets of a company in today’s scenario with increase in infrastructure, heavy demand with increase in complexity of construction,
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construction plant and equipment has become integral part of every project. In construction, plant and equipment contribute a great deal towards speed, quality, safety and efficiency of a project.
The mechanization began to show up in the 1960's in construction projects. Initially, government bodies such as Ministry of Surface Transport (MOST) and Public Works Department (PWD) imported equipments and hired them out to contractors for execution of works. The market was accordingly limited in scope. In the 1980's, the projects began to be increasingly granted on turnkey basis. Project sizes also became larger and external funding agencies started mandating the use of appropriate equipments for works funded by them. Gradually, one of the criteria for pre-qualification of contractors became the ownership of equipments. Faster project execution required state-of-the-art equipment. The average unit cost of construction equipment in the construction works became around 15 to 20 percent.
2.2
ADVANTAGES AND DISADVANTAGES OF USING EQUIPMENTS
The construction planning and execution is a synthesis if speed, safety, efficiency economy, and the use of equipments offers some advantages. However there are some severe handicaps with the usage of equipments, especially in developing countries.
2.2.1 Advantages of using machines
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− Use of machines helps in speedy construction and thereby the project facility starts to give returns earlier as compared to manual construction, which consumes much more time.
− Economic considerations of early completion such as reduction in overheads, less escalation etc.
− Machines are capable of handling tough work and can be expected with a fair degree of effectiveness.
− While the availability of human labor is sometimes uncertain, machines are dependable and are unaffected by social and economic conditions of the region.
− Where the work involved includes large quantities to be handled for long distances, machines work out to be cheaper.
− Machine’s performance can be assessed more accurately than that of the human resource and thereby adherence to schedules is easier.
− Use of mechanical equipment has long range benefit in creating technical knowhow and skilled workmen who could prove assets in the country’s technical development.
− Use of indigenous machines reflects on the manufacturing industry and faster industrialization of the country.
2.2.2 Disadvantages of using machines
− Use of equipment results in dependence for supply of spare parts and specialists services of manufacturers. The non-availability of these things causes downtime and financial losses by way of lost working time.
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− Often the overall cost of working of machines has been found to be more than the first estimates showed. Some machines consume spare parts costing as much as 200 percent of original estimates.
− Sometimes the delay caused in procurement, trans-shipment, installation and commissioning may be more than offset the gain in time expected as a result of using equipment.
− The disposal of the equipment profitably after completion of a project may prove difficult, resulting in capital loss to the project. Similarly, disposal of large quantities of spare parts for obsolete models may pose serious problems.
− Where work can be successfully accomplished by manual labor, use of machines aggravates extent of unemployment and creates social problems.
2.3 GROWTH OF CONSTRUCTION EQUIPMENTS IN INDIA
India had only a few construction equipments, in the pre-independence period. The equipments were used for the first time in construction in India in 1913 and it was a steam driven crane. Later equipments like draglines and shovels were used in the construction of Sind Barrage Canal System. A gasoline tractor was used as a hauling unit in the year 1930-33. The first known ownership of construction equipment by a contractor was in 1937. There were only 23 machines of total value of Rs.25.28 lakhs with Irrigation Department and contractors all over India.
The gross value of equipment used in India also increased since independence. In 1950, India had 95 machines valued at Rs.0.421 crores, in 1960 it had 934
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machines valued at Rs.12 crores, in 1970 it went up to 643 machines valued Rs.21 crores and in 1979 it was 16048 machines valued Rs.297.5 crores. Of these l6048 machines, 1494 numbers valued at Rs.26.35 crores were owned by private companies, 7134 machines valued Rs.132.73 crores were owned by State Governments and the remaining by the Central Government. Out of the total stock of equipments in 1979, 74 percent of equipment by value was imported and these were mostly excavators, tractors, dumpers, scrapers, graders and loaders. Equipments like cranes, locomotives, belt conveyors, vibratory rollers, fork lifts and pile driving equipment were imported even though indigenous stock was in hand. Some equipment like cableways, rocker shovels, ditchers and trenchers, asphalt distribution, paver finishers and spreaders were totally imported. Thus, the import component of construction equipment in India remained high till 1979. Rapid indigenisation took place thereafter. The domestic production of construction equipment reached nearly USD 1.9 billion in 2000, from the previous year's output of USD 1.6 billion. The expanding construction market is pushing up the production of technologically advanced machinery in India. Currently Indian firms manufacture a limited range of construction equipment. Major construction equipment manufacturing companies are Bharat Earth Movers Limited (BEML), Heavy Engineering Corporation, Hindustan Motors (HM), Larsen and Turbo (L & T), Escorts JCB, Ingersoll Rand etc. Other prominent manufacturers of construction equipment in the mid segment are Condequip, Alien Buildwell, Gujarat Apollo, Ashok Engineering, Leo Road Equipments, and Jaypee etc. Many of these companies have technical collaboration with foreign firms. The growth of construction equipments by value
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during the period 1940-2000 is taken from “Construction Equipment Industry in India” By Mr. Ramesh Babu in March 2003 shown in Table 2.1.
TABLE 2.1GROWTH OF CONSTRUCTION EQUIPMENTS BY VALUE 19402000 SI.No
Year
Machines (Nos.)
Value (Crores)
1. 2.
1940 1945
2 2
0.0074 0.0040
3.
1950
95
0:421
4.
1955
238
1.62
5.
1960
934
12.04
6. 7. 8.
1965 1970 1979
2197 643 16048
38.71 21.06 297.54
9. 10. 11.
1984 1998 1999
N.A. N.A. N.A.
408.44 6600.00 8000.00
12.
2000
N.A.
9870.00
Table 2.1 is referred from “Construction equipment Industry in India” by Mr. Ramesh Babu in the year 2003
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Government, though belatedly, has assigned the topmost priority for development of infrastructure in the country and the result is the launching of numerous ambitious projects such as Golden Quadrilateral and North – South and East-West Corridor under National Highways Development Project (NHDP), Pradhan Mantri Gram Sadak Yojana (PMGSY) and the River Interlinking to name a few. Besides, Government has taken initiatives for private sector participation, loan assistance from external agencies, like, World Bank, Asian Development Bank, Japan Bank for International Cooperation.
This goal can be achieved only by mechanized construction as only modern high performance construction machinery can ensure process control in real time for achieving end product quality conforming to design specifications. For speedy construction works to complete the project within a fixed time frame, deployment of adequate and appropriate machinery has to be ensured. Moreover, mechanized construction aims at technology up gradation. Table 2.2 is referred from “Construction equipment Industry in India” by Mr. Ramesh Babu in the year 2003
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TABLE 2.2. POPULATION OF CONSTRUCTION EQUIPMENTS IN INDIA DECEMBER 2001 Sr. No.
Equipment
Number
1.
Mobile
15000
2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
Mini Wheeled Crawler Crawler Crawler Wheeled Backhoe Skid-Steer Rough Dum Trucks Motor Motor Mobile As halt Compaction Total
200 200 1 2000 8000 160 6000 15000 130 90 10000 750 200 8100 1400 22000 99230
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TABLE 2.3 PROJECTED SALES OF CONSTRUCTION EQUIPMENT AND MACHINES IN INDIA 2001-05 (Nos.) Sr.
Equipment
No.
Year 2001
2002
2003
2004
2005
1.
Mobile Cranes
585
600
615
650
690
2.
Mini Excavators
80
90
120
150
180
3.
Wheeled Excavators
5
5
5
10
5
4.
Crawler Excavators
1950
2100
2250
2400
2550
5.
Crawler Dozers
350
360
375
395
415
6.
Crawler Loaders
3
2
4
3
5
7.
Wheeled Loaders
400
420
480
530
580
8.
Backhoe Loaders
3500
3300
3000
3200
3500
9.
Skid-Steer Loaders
70
85
100
125
150
10.
Rough Terrain Lift Trucks -
1
2
1
3
11.
Dump Trucks
385
405
418
430
455
12.
Motor Graders
160
220
300
350
420
13.
Motor Scrapers
-
-
-
2
3
14.
Mobile Compressors
1680
1850
2000
2250
2400
15.
Asphalt Finishers
150
175
210
250
300
16.
Compaction Equipment
770
865
960
1130
1500
Total
10068
10478
10839
11876
13166
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Table 2.3 is referred from “Construction equipment and job planning” by Deodhar. S.V in 2nd edition 2001 TABLE 2.4 DEMAND PROJECTIONSROAD MACHINERY(YEARS 2000-15) Product
2005/6
2010/11
2015/16
Hydraulic Excavator
6225
9350
14000
10450
15700
Excavator
Loaders 6960
(Wheeled) TMB Front end Loaders
3225
4837
7255
Crawler Tractors &
1630
2450
3675
Mobile Cranes (Wheeled 2580
3870
5805
1340
2345
Dozers
and Crawler) Vibratory Rollers (6-10 760 tons) Soil & Asphalt Road Rollers (Static)
1000
1200
1400
Asphalt Pavers- Mech.
300
400
500
130
160
200
125
150
175
600
700
800
150
200
250
Hydrostatic Motor Graders Hot Mix Plants – PTO 15 T Above 20 T
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Table 2.4 is referred from “Construction equipment and job planning” by Deodhar. S.V in 2nd edition 2001
2.4
PLANNING FOR CONSTRUCTION EQUIPMENT
Equipment planning on major construction projects includes besides its selection, the decision about working shifts, number and size of machines, the matching of units working in a team, procurement schedule and the arrangement of necessary technical staff to operate, service and repair of the equipment. Planning of workshop and store facilities is also an important aspect of equipment planning.
The type of equipment selected for removal of soil usually depends upon soil and valley conditions and upon the characteristics of material to be handled. The number and size of machines selected depend upon the magnitude of work, working days available and number of shifts worked in a day. Size matching of all equipments working in a group is vital. The procurement plan must be in line with the construction schedule. Also, planned with equipment procurement should be the spare parts for it and supplies of fuels, oils, lubricants etc. for its operation. Suitable service facilities are vital to realize the planned output rate of equipments. Availability of operation and maintenance staff having adequate quality and number for the operation of equipment is essential to obtain full production. The use of mathematical models of the operation of equipment can be used for planning and selection of construction equipment.
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Equipment planning shall include the following aspects.
− Selection of equipment. − Number and sizes of units. − Matching capacities. − Schedule of procurement. − Arrangement of skilled staff for operation and maintenance. − Establishment of service and repair facilities. − Maintenance of spare parts inventory. − Decision regarding number of shifts per operation.
A systematic approach in respect of planning for equipment is necessary, incorporating all the factors detailed above. In addition an important factor to be considered is the necessary inter-disciplinary acceptance of the planning for equipment. In a majority of the cases a Civil Engineer may head project whereas the construction equipment management will demand close liaison with mechanical and electrical engineers. It will be prudent to have detailed consultations among the disciplines before the final choice of the equipment.
2.5
SELECTION OF EQUIPMENT
A contractor is frequently confronted with the problem of the selection of the most suitable equipment as he plans to execute the project. Equipment purchase
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involves initial heavy investments. In the long run, equipment adds to the profitability by reducing the overall costs, provided the equipment is properly planned, technically scrutinized, economically procured and effectively managed. Poor selection and bad management of equipment are generally attributed to task mismatch, unplanned requirement forecasts, hasty purchase decisions, inadequate repairs and spares supply, and lack of maintenance. The rapid development in equipment technology during the past several decades has brought in to market wide range of equipment making their selection more and more difficult.
The proper selection of equipment judicious deployment of the same on work is one major factor, which will go a long way in helping the contractor to maintain the completion targets of his contract within the estimated cost. Selection of an equipment to perform an assigned task depends on many interrelated factors. These factors are outlined in further sections.
2.5.1
Task Considerations
− Nature of task and specifications. − Daily or hourly forecast of planned production. − Quantity of work and time allowed for completion. − Distribution of work at site. − Interference expected and interdependence with other operations.
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2.5.2
Site Constraints
− Accessibility to location. − Maneuverability at site. − Working space restrictions. − Altitude and weather conditions. − Working season and working hours. − Availability of local resources of manpower, materials and equipment. − Availability of equipment hiring. Repair and maintenance facilities, locally. − Availability of fuel, oil and lubricants.
2.5.3
Equipment Suitability
− Type of equipment considered suitable for the task. − Make models and sizes of special purpose, and general-purpose equipment available that can handle the task.
− Production capability, serviceability condition and delivery time of each equipment available.
− Equipment already owned by the contractor. − Usefulness of the suitable equipment available for other and future tasks.
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2.5.4
Operating Reliability
− Manufacturer’s reputation. − Equipment components, engine-transmission, brakes, steering operator’s cabin. − Use of standard components. − Warranties and guarantees. − Vendors after sale service. − Operator’s acceptability, adaptability and training requirements. − Structural designs. − Preventive maintenance programme. − Safety features. − Availability of fuel, oil and lubricants. − Maintainability: − Ease of repair and maintenance. − Vendors after sales and service, repairs, spares and maintenance. − Availability of spare parts. − Standardization consideration.
2.5.5
Economic Considerations
− Owning costs.
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− Operating costs. − Re-sale or residual value after use. − Replacement costs of existing equipment. − Unit cost of production.
2.5.6
Commercial Considerations
− Use of available equipment. − Buy second-hand or new equipment. − Rent equipment. − Hire-purchase equipment. − Purchase or lease.
Equipment selection analysis considers various factors but not necessarily limited to the above mentioned. It leads to alternatives for acquiring the required equipment. It is then for the management to make decision after careful consideration of all the facts. In most cases the final equipment selection decision is likely to be a compromise between what is ideally required and what can actually be obtained economically.
2.6
ESTABILISHMENT OF EQUIPMENT PERFORMANCE NORMS
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Selection of equipment needs careful thought to ensure efficient and effective performance. Though the actual selection would depend on factors like type of work and its magnitude, location etc. Certain guidelines can be laid down. 2.6.1
Equipment Acquisition Options
A project has multifarious activities where plant can be employed effectively and efficiently, but this does not justify purchasing plant to perform all activities. Purchase of plant requires heavy investment of capital, and no contractor can afford the luxury of owning all types of plant and machinery required in a project. Contractors have a number of options for acquiring plant. These include the following: 1) Purchase
− Outright − Guaranteed buy-back 2) Renting 3) Leasing and Hire-Purchase 4) Outsourcing
2.6.2 Spare Parts and Inventory Control
This is a job, which needs the exact balance between availability of spares and low inventory cost. On one hand it should provide proper assurance for availability of desired spare parts in proper time and quantity. And on other hand
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should not result in excessive stocking or blocking up of capital. Proper planning is very essential to get the best result.
2.6.3
Equipment maintenance Plan
The Maintenance plan determines the quality of maintenance work. A singular aspect of maintenance activities is the difficulty of accessing the quality of work done. If maintenance work is poorly done it may lead to a breakdown because of the intervening time lag, whoever it is hard to judge whether the breakdown was due to maintenance errors or defective parts. In other words the quality of maintenance must assure the quality of the work itself. To accomplish thus, each individual member of the maintenance crew must have sense of responsibility and consider methods for preparing, executing, and validating his or her own work.
From standpoint of efficiency, work planned for in advance can be accomplished for more quickly than work done in relation to abrupt failure. To raise the level of maintenance, quality and efficiency, it is essential to create a maintenance plan and make tenacious preparation prior to its execution. When perusing planned maintenance the maintenance crew should say, “let’s curb breakdown”. The benefits of creating maintenance plan can be summarized as follows
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− The number of operational steps can be reutilized. − Human resource required can be planned so that required personnels are available.
− Errors in the procurement of material, spare parts and subcontracting work can be prevented.
− Quality can be checked and better material can be procured. − By devising related work detail plans, schedules can be set so that they are coordinated with production plans.
− Repair cycle can be identified so that measures can be taken in a timely fashion. − Standardization patterns for repair work can be identified enabling the work to be done efficiently.
− Simultaneously repair plans can be devised. − People’s sense of responsibility can be encouraged. − Through planned work activities large volume of work can be more efficiently accomplished.
2.7
ECONOMICS OF CONSTRUCTION EQUIPMENT
Economics of construction equipment is a study of the cost accounting process pertaining to the working of the machinery and includes computation of plant use rates and unit cost of production. The investment criteria with a view to acquire a piece of equipment or to retire it based on economic evaluation may also be included under equipment economics. Another aspect of the cost accounting process is the up-keep of records pertaining to equipment. Without these records it would be
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impossible to control equipment costs and valuable information necessary in future equipment selection would be lost. Hourly owning and operating costs for a given machine can vary widely because they are influenced by many factors
− Cost of equipment delivered to owner − Conditions under which it is used − Number of hours it is used per year − Number of years it is used − Maintenance and repair for the equipment − Demand for the used equipment when it is sold, which will affect the salvage value
In order to optimize the procurement and utilization of the construction equipment, it is necessary to understand the various factors of cost of using the equipment. The various factors are listed subsequent sections.
2.7.1
Ownership Cost
The ownership costs are in the nature of fixed costs, as they have to be incurred irrespective of the quantum of use. These are real costs as far as an organization is concerned but they are notional for a site. They are also called as Performa charges.
− Depreciation − Interest
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− Insurance and storage − Transport and setting up − Miscellaneous and overhead.
2.7.2
Operating Cost
The operation costs are directly related to the quantum of use and efficiency of the equipment. These costs are normally incurred by the sites and are too apparent and real.
− Fuel and Energy − Lubricants − Spares and Consumables − Operating Manpower − Repair Manpower − Miscellaneous and Overhead Total equipment cost = Ownership cost+ Operating cost
2.8 EQUIPMENT MAINTENANCE
Maintenance of a piece of equipment is the operation of keeping its various components in their original form as far as possible with the view to ensure that safety and production in operation do not deteriorate. It includes servicing, inspection
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and adjustment, small repairs in the field, major repairs and overhaul in main workshops and proper is of laid-up machine. The objective of maintenance would be:
− To maximize availability of machinery and facilities needed for smooth production.
− To minimize downtime due to breakdown of machinery. − To ensure long life of the machinery to avoid high rate of depreciation of capital.
2.9 NEED FOR EQUIPMENT RECORDS AND WORKSHOPS
Construction is the ultimate objective of a design and machines make accomplishment of that objective possible. Mechanized construction is indispensable under certain conditions for quick, efficient and quality oriented execution of the projects. The ability to win contracts and to perform them at a profit is determined for the construction contractor by two vital assets: people and equipment. To be economically competitive, a contractor’s equipment must be competitive, both mechanically and technologically. Optimizing in the management of an equipment spread is critical for a contractor in achieving a competitive pricing position.
In order to achieve this, it is essential that there is in place a system that provides with the required data for making rational equipment decisions. Records are the basic documents that provide these vital data and therefore it is essential to ensure that records are designed and in place to serve the purpose.
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Machinery and equipment which have become an integral part of any construction activity, and plants and machinery now constitute a substantial portion of the construction cost in a project (in tune of 15 to 20 percent of total project cost depending upon the extent of mechanization), has to be maintained to turn the project into a profit making center for any organization. The plant and machinery (P&M) workshops on site are the places wherein this maintenance are carried out and therefore it is necessary that the project sites are provided with a well planned and equipped P and M workshop.
CHAPTER 3
ESTABLISHING AND MANAGING THE MAINTENANCE FUNCTION
3.1.
INTRODUCTION
TO
THE
THEORY
AND
PRACTICE
OF
CONSTRUCTION EQUIPMENT MAINTENANCE
Equipment maintenance is not simply preventive maintenance, although preventive maintenance is an important ingredient. It is not lubrication, although lubrication is a function of maintenance. It is not a hasty rush to repair a broken machine part or replace a faltering bearing, although these are maintenance activities. Equipment maintenance is a science, an exercise in economics, and art, and a philosophy. Because maintenance is all these things and because too many practitioner treat it wholly as one of its components.
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3.2.
GENERAL DO’S AND DON’TS FOR MAINTENANCE
Do’s
− Do keep the equipment clean. − Do processes operation and maintenance manuals and be thorough with equipment manufacturer’s instruction.
− Do pay particular attention to lubrication. − Do use only genuine spares. − Do keep all nuts and bolts tight. − Do examine engine oils and radiator water daily, before starting equipment. − Do attend periodic preventive maintenance. − Do take steps to keep all meter and safety device working.
Don’ts
− Don’t overload engine and equipment. − Don’t run engine if black smoke is coming out of exhaust. − Don’t use cotton waste, while cleaning engine parts. − Don’t mix different brands of oils. − Don’ t observe economy only in cost of maintenance − Don’t store fuel, oil in galvanized containers.
3.3 PRECAUTION FOR MAINTENANCE
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Before carrying out maintenance
− Notification of failure should be given to proper person who has an in depth knowledge of the equipment.
− Warning tags showing “Do not operate “should be attached on work equipment, so that no one tries to operate the equipment unknowingly.
− Clean before inspection and maintenance. − Keep work place clean and tidy. − Take care that enough fire fighting arrangement is established and restriction of smoking is initiated.
− Take care that the engine is stopped before carrying out inspection and maintenance.
− See whether proper rigging tools, repair tools are present at workshop and at site before carrying out maintenance work.
During maintenance
− Only authorized persons should be allowed to attend to the maintenance of equipment.
− Store attachments in safe place and restrict unauthorized persons to go close to it. − While working under machine take care that the equipment is placed on firm level ground.
− Do not carry out maintenance with engine running, if it is necessary then take care that the operator is seated to stop the machine in case of emergency.
− Take care that no tools are left as it is inside the machine by mistake.
xxxiii
− Take care that the mechanics are provided with personal protective equipments. − Repair should be carried out as soon as abnormality i s reported. − Precaution should be taken while handling fuel, high-pressure hoses, high pressure oils, and while carrying out maintenance at high temperature.
3.4
IMPORTANCE OF WORKSHOP LAYOUTS
3.4.1 Introduction
The Plant and Machinery (P&M) workshops are the places wherein the maintenance is carried out and therefore it is necessary that the projects are provided with a well planned and equipped P&M workshop. These workshops should be designed to meet the requirement of Inspection, Maintenance and Repair of equipments. A well-equipped workshop with well-trained technical manpower will develop confidence in the project team to complete the project in time.
3.4.2 Light repair workshop
The light repair workshops (Type A) are located in temporary accommodation or on wheels at the Project Site. These workshops carry out inspection, servicing and light repairs to equipments and are equipped with fast moving spares for light repairs and few minor assemblies.
xxxiv
3.4.3 Field repair workshop
The field repair workshops (Type B) are generally located in zonal areas of the company giving repair and maintenance cover to the projects in and around that zone. These workshops are semi-state with full range of repair and maintenance equipments. The workshop is stocked with adequate spares and assemblies for replenishing the light repair workshops..
3.5
PROCEDURE FOR MAINTENANCE OF WORKSHOP
The following procedure is generally followed in workshops for repair and maintenance.
− The user sends the equipments for repairs/maintenance to the workshops with a work order indicating likely defects in the equipment.
− The Receipt and Inspection (R & I) Section acknowledges the work order. − The Inspection section carries out a thorough inspection of the defective equipment and prepares a detailed defect list.
− The Receipt and Inspection (R & I) section prepares a repair card listing all defects in the equipment.
− The defective equipment is moved to respective repair bays where it shall be attended by mechanics under the supervision of shop foreman.
xxxv
− The spares required for repair are drawn from the stores and old spares returned to stores.
− The shop foreman carries out a preliminary test on the repaired equipment and then sends the equipment to the inspection team in R & I section for final testing.
− The Receipt and Inspection(R & I) team finally carries out the inspection of the equipment and endorses fitness certificate on the repair card.
− The Receipt and Inspection (R & I) section closes the repair card after final tests and records all repairs carried out and spares fitted in
the log book of the
equipment.
− In case of major repairs beyond the scope of the workshop, the equipment is sent to the next higher workshop by the inspection team after the approval of the workshop officer.
− The inspection team also determines the final classification of equipments based on usage and major repairs.
3.6
PLANT ASSESSMENT AND BENCHMARKING
Next, current capabilities in each of the three major maintenance components, have to be accessed
− Maintenance processes − Maintenance resources − Maintenance technology Use the assessment to identify missing capabilities so that we can develop or procure them. Include training requirements and subcontracted service needs. Our
xxxvi
maintenance technology should be able to support predictive and proactive maintenance. The assessment also helps us to determine future exposure — the loss of critical in-house skill sets, especially through attrition and retirement. The best solution may be to design unique requirements out of the plant. Benchmarking can be a useful part of our assessment. It compares our operation to other plants — not to outdo them, but to identify best practices and useful strategies that can help us improve. Here are some examples:
TABLE 3.1 MAINTENANCE COST BENCHMARKS
General cost ratios
Best practice
Total maintenance cost / 3.4%
Range
1.5 - 5.0%
total output Total maintenance cost / 2.3% Estimated
2.0 - 5.0%
Replacement
Value Maintenance labor cost /
1.5%
0.6 - 2.1%
Maintenance material cost 1.9%
0.8 - 2.4%
total output
xxxvii
/ total output
www.assetweb.com
TABLE 3.2 MAINTENANCE BENCH MARKS
Maintenance Performance
Best Practice
Range
Work order coverage
95%
80 - 95%
Scheduled compliance
>70%
35 - 70%
Preventive maintenance
95%
80 -100%
Planned work
95%
65 - 95%
Uptime
>78%
48 - 78%
Predictive
+
preventive 25%
10 - 25%
maintenance by operators 40% Predictive maintenance hours/total hours
+
preventive labor maintenance
18-40%
xxxviii
www.assetweb.com
3.6.1 Making Maintenance Work Processes More Efficient
Although maintenance management systems can help us reduce costs, we can make substantial reductions even before introducing such a system by carefully examining current maintenance work processes and changing the way some things are done. In fact, making work processes more efficient is the first step toward realizing the full potential of automated maintenance systems. We have to ask our self these questions:
− What phases of the maintenance process offer opportunities for improvement? − Which maintenance projects can probably be eliminated? − How can work analysis reduce maintenance costs?
3.6.2
Making Maintenance resources.
One of the steps in the work process methodology is maintenance resource optimization.
Measurable results
xxxix
Any worthwhile change should add value to the operation — whether that value takes the form of reduced labor, longer equipment service life, less frequent repairs to specific instruments, improved product quality, or greater plant throughout. The implementation team should therefore establish goals and a way to measure progress toward them.
Typically, after six months the implementation team should be able to evaluate the results of any change and determine precisely how well the organization has performed with respect to that particular goal. In cases where work processes extend maintenance intervals beyond six months, the evaluation period may be longer.
Of course, measurement depends on the availability of data, which the Maintenance Management System should be able to supply. Make sure you select a system capable of the necessary data indexing and retrieval — and make sure consistent, accurate data entry is part of employee training in the new work processes.
xl
CHAPTER 4
EQUIPMENT
DETAILS
OF
THE
TWO
CONSTRUCTION
COMPANIES
4.1
INTRODUCTION
This chapter involves the equipment details and its usage in a month for both the construction companies i)M/S Larsen & Toubro Ltd (L & T)
ii)
Consolidated Construction Consortium Ltd (CCCL). After the collection of data and calculating and comparing them, the overall maintenance cost and its percentage over the total expenditure of each equipment are found out. Table 4.1 shows the list of equipments in L&T and their capacity and identification. Table 4.2 shows the list of equipments in CCCL and their capacity and identification. Table 4.3 shows the comparison of the maintenance cost of each equipment and its details for both the companies Table 4.4 and 4.5 show the usage of equipments in a particular month for various projects and manually calculated breakdown maintenance cost, breakdown working hours, total maintenance cost, percentage maintenance cost and average working hours for L & T and CCCL companies respectively.
xli
Table 4.6 shows the comparison of the maintenance cost and its percentage for concrete mixing equipments in both the companies. Table 4.7 shows the comparison of the maintenance cost and its percentage for earth moving equipments available in both the companies. Figure 4.1 shows the comparison of the total number of concrete mixing equipments available in both the companies. Figure 4.2 shows the comparison of the maintenance cost for each equipment of the various concrete mixing equipments for both the companies. It is clear that L&T spends more for maintaining all the concrete mixing equipments in general and particularly more for concrete pumps (200% more than CCCL). Figure 4.3 shows the comparison of the total number of earth moving equipments available in both the companies. Figure 4.4 shows the comparison of the maintenance cost for each equipment of the various earth moving equipments for both the companies Table 4.8 which is the final stage in this chapter gives the overall maintenance cost in both the companies and also the overall percentage maintenance cost per month.
xlii
TABLE 4.1. LIST OF EQUIPMENTS IN THE L&T COMPANY
S No
Name Of the Equipment
Nos
Capacity
Identification
1
Dozers
5
BEML(D155)
2
Dozers
12
BEML(D80)
3
Motor Graders
27
155HP
BEML(GD 605R2)
4
Motor Graders
10
155HP
KOMATSU
5
Wheel Loaders
22
1.7cum
HM20-21
6
Wheel Loaders
8
1.7cum
L&T CASE W20
7
Excavator
13
900Lit
L&T Proclain
8
Back Hoe(Loader)
2
1.00cum
JCB
9
Back Hoe(Loader)
14
1.00cum
L&T case 580
10
Vibratory Rollers
40
10 Tonnes
L&T Vibromax
11
Vibratory Rollers
13
2.7Tonnes
Bomag
12
Heavy Crane
3
250 Tonnes
American
13
Heavy Crane
1
750 Tonnes
Link Belt
14
Crane(18LPH)
56
75 Tonnes
TATA 955
15
Crane(8LPH)
69
18 Tonnes
TATA 320
16
Crane(6LPH)
10
20 Tonnes
COLES 620
17
Crane(4LPH)
70
8 Tonnes
ESCORTS
18
Truck
70
10 Tonnes
Ashok Leyland
xliii
19
Mini Truck
18
6 Tonnes
TATA(407)
20
Tipper
76
6cum
TATA
21
Tipper
119
6cum
Ashok Leyland
22
Water Tankers
47
10000Lit
Ashok Leyland
23
Batching Plant
30
30cum
STETTER
24
Batching Plant
24
30cum
MILLERS
25
Concrete pump
44
56cum
STETTER
26
Hot Mixer Plant
1
120 Tonnes
LINHOFF
27
Hot Mix Plant
1
135 Tonnes
MARINI
28
Hot Mix Plant
3
90 Tonnes
Condecup
29
WMM Paver
3
60 Tonnes
Gujarat Apollo
xliv
TABLE 4.2.
S no
LIST OF EQUIPMENTS IN THE CCCL COMPANY
Name of the Nos
Capacity/hp
equipment
Make identification
1
Crane
5
20 MT
Komatsu
2
Crane
1
30 MT
Tfi
3
Crane
2
75 MT
Tata
4
Crane
1
20 MT
Navin
5
Concrete
1
30 cum/hr
Greaves
2
52 cum/hr
Schwing
pumps 6
Mobile concrete pumps
7
Wheel dozers
6
2 MT
Tata
8
Wheel dozers
10
2 MT
Hindustan
9
Wheel dozers
3
3 cum
Volvo
10
Excavator
3
0.9 cum
Cater pillar
11
Excavator
2
200 hp
Cater pillar
12
Excavator
5
200 hp
Samsung
13
Excavator
2
300 hp
Daewoo
xlv
14
JCB
5
0.6 cum
Escort
15
JCB
2
0.6 cum
Tata
16
Motor graders
3
120 hp
Komatsu
17
Motor graders
13
120 hp
Cater pillar
18
Vibratory
10
10 MT
Greaves
4
10 MT
Escorts
1
10 MT
Kirloskar
rollers 19
Vibratory rollers
20
Vibratory rollers
21
Water tankers
41
10 KL
Tata
22
Water rankers
5
12 KL
Ashok Leyland
23
Tandem rollers
5
10 MT
Escorts
24
Tandem rollers
4
4 MT
Escorts
25
Tipper truck
110
10 MT
Tata
26
Tipper truck
20
25 MT
Ashok Leyland
27
Concrete paver
2
Wirtgen
28
Texturing and 2
wirtgen
curing machine
xlvi
TABLE 4.3.
COMPARISION OF BOTH THE COMPANIES EQUIPMENTS MAINTENANCE COST
EQUIPMENTS
TOTAL
TOTAL
NAME
EQUIPMENTS MAINTENANCE MAINTENANCE COST NOS
%
MAINTENANCE
COST(Rs)
FOR
EACH EQUIPMENT(Rs)
CCCL
L&T
CCCL
L&T
CCCL
L&T
CCCL
L&T
TIPPER
130
195
135200
276900
0.70%
1.07%
1040
1420
EXCAVATOR
12
13
37308
54560
1.38%
5.08%
3109
4127
BACK
7
16
5810
37280
1.04%
4.70%
830
2330
16
37
67360
364450
2.23%
10.85%
4210
9850
3
44
3450
154000
0.50%
3.92%
1150
3500
24
53
25200
106000
1.59%
3.78%
1050
2000
46
47
56580
66740
3.09%
1.72%
1230
1420
CRANE
9
205
7200
282900
4.22%
8.80%
800
1380
WHEEL
19
17
315096
26860
12.56%
1.995
16585
1580
HOE(JCB) MOTOR GRADERS CONCRETE PUMPS VIBRATORY ROLLERS WATER TANKERS
xlvii
DOZERS TABLE 4.6.
COMPARISION OF THE MAINTENANCE COST AND ITS PERCENTAGE FOR CONCRETE MIXING EQUIPMENTS.
EQUIPMENTS
TOTAL
NAME
NUMBER
CONCRETE
TOTAL
% MAINTENANCE
OF MAINTENANCE
MAINTENANCE COST FOR EACH
EQUIPMENTS
COST(Rs)
EQUIPMENT(Rs)
CCCL
L&T
CCCL
L&T
CCCL
L&T
CCCL
L&T
3
44
3450
154000
0.50%
3.92%
1150
3500
24
53
25200
106000
1.59%
3.78%
1050
2000
5
13000
24000
3.8%
3.6%
4350
4800
PUMPS VIBRATORY ROLLERS HOT
MIX 3
PLANT
COMPARISON OF NO OF EQUIPMENTS 60 50 40
NUMBERS 30 CCCL L&T
20 10 0 CONCRETE VIBRATORY PUMPS ROLLERS
HOT MIX PLANT
NAME OF THE EQUIPMENT
xlviii
Figure 4.1. Comparison of total number of concrete mixing equipments
COMPARISON OF MAINTENANCE COST FOR EACH EQUIPMENT
5000 4500 4000 3500 3000
COST(Rs) 2500 CCCL
2000
L&T 1500 1000 500 0 CONCRETE
VIBRATORY
HOT MIX
PUMPS
ROLLERS
PLANT
NAME OF EQUIPMENT
Figure 4.2 Comparison of maintenance cost for each concrete mixing equipment
xlix
TABLE 4.7
COMPARISION OF THE MAINTENANCE COST AND ITS PERCENTAGE FOR EARTH MOVING EQUIPMENTS.
EQUIPMENTS
TOTAL
NAME
NUMBER
TIPPER
TOTAL OF MAINTENANC
%
MAINTENANCE
COST
MAINTENANCE
FOR
EACH
EQUIPMENTS
E COST(Rs)
EQUIPMENTS(Rs)
CCCL
L&T
CCCL
L&T
CCCL
L&T
CCCL
L&T
130
195
135200
27690
0.70%
1.07
1040
1420
3109
4127
830
2330
0 EXCAVATOR
12
13
37308
54560
% 1.38%
5.08 %
BACK HOE(JCB)
7
16
5810
37280
1.04%
4.70 %
l
Comparison of No. of Equipment
200 180 160 140 120
No.of Equipm ent 100
CCCL
80
L&T
60 40 20 0 Tipper
Excavator
Back Hoe
Name of the Equipment
Figure 4.3 Comparison of total number of earth moving equipments
COMPARISON OF MAINTENANCE COST OF EACH EQUIPMENT
I
4500 4000 3500 3000 2500
COST(RS)
CCCL
2000
L&T
1500 1000 500 0 TIPPER
EXCAVA TOR
BACKHOE
NAM E OF THE EQUIPM ENT
Figure 4.4 Maintenance cost for each earth moving equipment
li
TABLE 4.8. COMPARISION OF OVERALL MAINTENANCE COST
PARAMETERS
CCCL
L&T
OVERALL TOTAL MAINTENANCE COST PER MONTH
Rs 653204.00
Rs 1369690.00
OVERALL TOTAL MAINTENANCE COST PER DAY
Rs 21775.00
Rs45655.00
3.04
4.65
OVERALL PERCENTAGE MAINTENANCE COST PER MONTH
CHAPTER 4
EQUIPMENT
DETAILS
COMPANIES
4.2
INTRODUCTION
OF
THE
TWO
CONSTRUCTION
lii
This chapter involves the equipment details and its usage in a month for both the construction companies i)M/S Larsen & Toubro Ltd (L & T)
ii)
Consolidated Construction Consortium Ltd (CCCL). After the collection of data and calculating and comparing them, the overall maintenance cost and its percentage over the total expenditure of each equipment are found out. Table 4.1 shows the list of equipments in L&T and their capacity and identification. Table 4.2 shows the list of equipments in CCCL and their capacity and identification. Table 4.3 shows the comparison of the maintenance cost of each equipment and its details for both the companies Table 4.4 and 4.5 show the usage of equipments in a particular month for various projects and manually calculated breakdown maintenance cost, breakdown working hours, total maintenance cost, percentage maintenance cost and average working hours for L & T and CCCL companies respectively.
Table 4.6 shows the comparison of the maintenance cost and its percentage for concrete mixing equipments in both the companies. Table 4.7 shows the comparison of the maintenance cost and its percentage for earth moving equipments available in both the companies. Figure 4.1 shows the comparison of the total number of concrete mixing equipments available in both the companies. Figure 4.2 shows the comparison of the maintenance cost for each equipment of the various concrete mixing equipments for both the companies. It is clear that
liii
L&T spends more for maintaining all the concrete mixing equipments in general and particularly more for concrete pumps (200% more than CCCL). Figure 4.3 shows the comparison of the total number of earth moving equipments available in both the companies. Figure 4.4 shows the comparison of the maintenance cost for each equipment of the various earth moving equipments for both the companies Table 4.8 which is the final stage in this chapter gives the overall maintenance cost in both the companies and also the overall percentage maintenance cost per month.
TABLE 4.1. LIST OF EQUIPMENTS IN THE L&T COMPANY
S No
Name Of the Equipment
Nos
Capacity
Identification
1
Dozers
5
BEML(D155)
2
Dozers
12
BEML(D80)
liv
3
Motor Graders
27
155HP
BEML(GD 605R2)
4
Motor Graders
10
155HP
KOMATSU
5
Wheel Loaders
22
1.7cum
HM20-21
6
Wheel Loaders
8
1.7cum
L&T CASE W20
7
Excavator
13
900Lit
L&T Proclain
8
Back Hoe(Loader)
2
1.00cum
JCB
9
Back Hoe(Loader)
14
1.00cum
L&T case 580
10
Vibratory Rollers
40
10 Tonnes
L&T Vibromax
11
Vibratory Rollers
13
2.7Tonnes
Bomag
12
Heavy Crane
3
250 Tonnes
American
13
Heavy Crane
1
750 Tonnes
Link Belt
14
Crane(18LPH)
56
75 Tonnes
TATA 955
15
Crane(8LPH)
69
18 Tonnes
TATA 320
16
Crane(6LPH)
10
20 Tonnes
COLES 620
17
Crane(4LPH)
70
8 Tonnes
ESCORTS
18
Truck
70
10 Tonnes
Ashok Leyland
19
Mini Truck
18
6 Tonnes
TATA(407)
20
Tipper
76
6cum
TATA
21
Tipper
119
6cum
Ashok Leyland
22
Water Tankers
47
10000Lit
Ashok Leyland
23
Batching Plant
30
30cum
STETTER
24
Batching Plant
24
30cum
MILLERS
25
Concrete pump
44
56cum
STETTER
lv
26
Hot Mixer Plant
1
120 Tonnes
LINHOFF
27
Hot Mix Plant
1
135 Tonnes
MARINI
28
Hot Mix Plant
3
90 Tonnes
Condecup
29
WMM Paver
3
60 Tonnes
Gujarat Apollo
lvi
TABLE 4.2.
S no
LIST OF EQUIPMENTS IN THE CCCL COMPANY
Name of the Nos
Capacity/hp
equipment
Make identification
1
Crane
5
20 MT
Komatsu
2
Crane
1
30 MT
Tfi
3
Crane
2
75 MT
Tata
4
Crane
1
20 MT
Navin
5
Concrete
1
30 cum/hr
Greaves
2
52 cum/hr
Schwing
pumps 6
Mobile concrete pumps
7
Wheel dozers
6
2 MT
Tata
8
Wheel dozers
10
2 MT
Hindustan
9
Wheel dozers
3
3 cum
Volvo
10
Excavator
3
0.9 cum
Cater pillar
11
Excavator
2
200 hp
Cater pillar
12
Excavator
5
200 hp
Samsung
13
Excavator
2
300 hp
Daewoo
14
JCB
5
0.6 cum
Escort
15
JCB
2
0.6 cum
Tata
16
Motor graders
3
120 hp
Komatsu
lvii
17
Motor graders
13
120 hp
Cater pillar
18
Vibratory
10
10 MT
Greaves
4
10 MT
Escorts
1
10 MT
Kirloskar
rollers 19
Vibratory rollers
20
Vibratory rollers
21
Water tankers
41
10 KL
Tata
22
Water rankers
5
12 KL
Ashok Leyland
23
Tandem rollers
5
10 MT
Escorts
24
Tandem rollers
4
4 MT
Escorts
25
Tipper truck
110
10 MT
Tata
26
Tipper truck
20
25 MT
Ashok Leyland
27
Concrete paver
2
Wirtgen
28
Texturing and 2
wirtgen
curing machine
TABLE 4.3.
COMPARISION OF BOTH THE COMPANIES EQUIPMENTS MAINTENANCE COST
lviii
EQUIPMENTS
TOTAL
TOTAL
NAME
EQUIPMENTS MAINTENANCE MAINTENANCE COST NOS
%
MAINTENANCE
COST(Rs)
FOR
EACH EQUIPMENT(Rs)
CCCL
L&T
CCCL
L&T
CCCL
L&T
CCCL
L&T
TIPPER
130
195
135200
276900
0.70%
1.07%
1040
1420
EXCAVATOR
12
13
37308
54560
1.38%
5.08%
3109
4127
BACK
7
16
5810
37280
1.04%
4.70%
830
2330
16
37
67360
364450
2.23%
10.85%
4210
9850
3
44
3450
154000
0.50%
3.92%
1150
3500
24
53
25200
106000
1.59%
3.78%
1050
2000
46
47
56580
66740
3.09%
1.72%
1230
1420
CRANE
9
205
7200
282900
4.22%
8.80%
800
1380
WHEEL
19
17
315096
26860
12.56%
1.995
16585
1580
HOE(JCB) MOTOR GRADERS CONCRETE PUMPS VIBRATORY ROLLERS WATER TANKERS
DOZERS TABLE 4.6.
COMPARISION OF THE MAINTENANCE COST AND ITS PERCENTAGE FOR CONCRETE MIXING EQUIPMENTS.
lix
EQUIPMENTS
TOTAL
NAME
NUMBER
CONCRETE
TOTAL
% MAINTENANCE
OF MAINTENANCE
MAINTENANCE COST FOR EACH
EQUIPMENTS
COST(Rs)
EQUIPMENT(Rs)
CCCL
L&T
CCCL
L&T
CCCL
L&T
CCCL
L&T
3
44
3450
154000
0.50%
3.92%
1150
3500
24
53
25200
106000
1.59%
3.78%
1050
2000
5
13000
24000
3.8%
3.6%
4350
4800
PUMPS VIBRATORY ROLLERS HOT
MIX 3
PLANT
COMPARISON OF NO OF EQUIPMENTS 60 50 40
NUMBERS 30 CCCL
20
L&T
10 0 CONCRETE VIBRATORY PUMPS ROLLERS
HOT MIX PLANT
NAME OF THE EQUIPMENT Figure 4.1. Comparison of total number of concrete mixing equipments
lx
COMPARISON OF MAINTENANCE COST FOR EACH EQUIPMENT
5000 4500 4000 3500 3000
COST(Rs) 2500 CCCL
2000
L&T 1500 1000 500 0 CONCRETE
VIBRATORY
HOT MIX
PUMPS
ROLLERS
PLANT
NAME OF EQUIPMENT
Figure 4.2 Comparison of maintenance cost for each concrete mixing equipment
lxi
TABLE 4.7
COMPARISION OF THE MAINTENANCE COST AND ITS PERCENTAGE FOR EARTH MOVING EQUIPMENTS.
EQUIPMENTS
TOTAL
NAME
NUMBER
TIPPER
EXCAVA EXCAVATOR TOR
TOTAL OF MAINTENANC
%
MAINTENANCE
COST
MAINTENANCE
FOR
EACH
EQUIPMENTS
E COST(Rs)
CCCL
L&T
CCCL
L&T
CCCL
L&T
CCCL
L&T
130
195
135200
27690
0.70%
1.07
1040
1420
3109
4127
830
2330
12
13
37308 373 08
EQUIPMENTS(Rs)
0
%
54560 545 60 1.38% 1.38%
5.08 5.08 %
BACK HOE(JCB)
7
16
5810 5810
3728 37280 0
1.04 1.04% %
4.70 4.70 %
lxii
Comparison of No. of Equipment
200 180 160 140 120
No.of Equipm Equipm ent 100
CCCL
80
L&T
60 40 20 0 Tipper
E x c avat or
B ac k Hoe
Name of the Equipment
Figure 4.3 Comparison of total number number of earth moving equipments equipments
COMPARISON OF MAINTENANCE COST OF EACH EQUIPMENT
I
4500 4000 3500 3000 2500
COST(RS)
CCCL
2000
L&T
1500 1000 500 0 TIP TIPPER
EXCAVA XCAVA TOR TOR
BACKH BACKHOE OE
NAM E OF THE EQUIPM EQUIPM ENT
Figure 4.4 Maintenance cost for each earth moving equipment
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TABLE 4.8. COMPARISION OF OVERALL MAINTENANCE COST
PARAMETERS
CCCL
L&T
OVERALL TOTAL MAINTENANCE COST PER MONTH
Rs 653204.00
Rs 1369690.00
OVERALL TOTAL MAINTENANCE COST PER DAY
Rs 21775.00
Rs45655.00
3.04
4.65
OVERALL PERCENTAGE MAINTENANCE COST PER MONTH
CHAPTER 5
FAILURE MODE EFFECT ANALYSIS (FMEA) AS A TOOL FOR CARRYING OUT MAINTENANCE COST
5.1. INTRODUCTION TO FAILURE MODE EFFECTS ANALYSIS
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A FMEA is a stable and seasoned design tool, Often called a Failure Mode Study, this design and maintenance engineering tool has existed and matured for some time, but is still ignored by many design teams and organizations.
While the last thing design, development and maintenance engineering needs is another acronym, Failure Mode and Effects Analysis (FMEA) may be one of the easiest concepts to understand and apply. Best of all, it delivers significant financial returns quickly.
Failure Mode and Effects Analysis is an approach that helps identify and prioritize potential equipment and process failures. Often used as a springboard to establishing a Root Cause Failure Analysis program, FMEA is a logical system that objectively ranks potential failures and provides recommendations for corrective actions. Informal failure analysis happens every day in most plants as engineers try to figure out why a machine unexpectedly broke down or how a part slowly came out of tolerance.
By contrast, FMEA is a formal process that allows in-house experts to concentrate on failures and fix them. Failure Mode and Effects Analysis is important because it focuses on failures and potential problems. If it's done early enough in the process, we can anticipate problems and engineer them out of the system. And the earlier you catch potential failures, the more money you save.
5.2
HISTORY OF FMEA
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The FMEA discipline was developed in the United States Military. Military Procedure MIL-P-1629, titled Procedures for Performing a Failure Mode, Effects and Criticality Analysis, is dated November 9th November 1949. It was used as a reliability evaluation technique to determine the effect of system and equipment failures. Failures were classified according to their impact on mission success and personnel/equipment safety. The term "personnel/equipment", taken directly from an abstract of Military Standard MIL-STD-1629, is notable. The concept that personnel and equipment are interchangeable does not apply in the modern manufacturing context of producing consumer goods. The manufacturers of consumer products established a new set of priorities, including customer satisfaction and safety. As a result, the risk assessment tools of the FMEA became partially outdated. They have not been adequately updated since.
5.3 TYPES OF FMEAS
− Design – Design FMEAs strive to eliminate causes of failure during equipment design, taking into account everything from ease of maintenance to potential safety concerns.
− Process – Process FMEAs focus on problems stemming from how the equipment is maintained and operated.
− System – System FMEAs look for potential failures and bottlenecks in larger processes, such as entire production lines.
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Many times the three levels overlap. They often happen simultaneously, particularly design and process FMEAs, because so much of the design depends on how the equipment is handled, and how it gets handled depends on design. Maintenance engineers are most often involved in process FMEAs, because equipment is usually installed and running by the time maintenance is asked to determine why a failure occurred. In a process FMEA, experts in other plant functions augment maintenance’s equipment expertise. A team consisting of a process engineer, a machinery operator and two maintenance people might conduct a maintenance-oriented process FMEA.
A cross-functional team of at least four members is recommended for any type of FMEA. Cross-functional teams are necessary for two reasons:
− No plant or machinery, function operates in a vacuum and it makes sense to get perspectives from other team members.
− Specific application expertise.
Education, background, work experience,
familiarity with past systems and failures. Each team member brings in another level of expertise.
5.4
WORKING OF FMEA
− Team isolates and describes the potential failure modes. − Team discusses the potential effect of each failure.
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− Team must assess the severity, occurrence and detection of failures and give those aspects different and meaningful numeric ratings. Ratings are typically from 1 to 10, with 1 being the least severe, least occurring, or most easily detectable. 10 would be those faults that are most severe, most catastrophic and those hardest to detect.
5.4.1
Isolate and Describe To determine a particular piece of equipment's risk of failure, team members
must first isolate and describe the potential failure mode: under what conditions does the equipment fail. In the case of a maintenance-related problem, this is often as simple as reviewing equipment history. In a design FMEA, this could include failure modes in the hardware, software, mechanical and system portions of the design.
5.4.2 Create severity, occurrence, and detection ratings.
Once the failure mode has been defined and the potential effects of failure have been determined, the team must assess the severity, occurrence and detection of failures and give those aspects numeric ratings. Severity means how serious the failure will be. Give it a rating from one to ten, where ten is the most severe failure.
In the same way, you rate the occurrence of failure - how frequently you see the failure. Detection indicates how easily that fault or failure can be detected. The detection scale is the reverse of the other 2 scales, with 1 being the easiest or most detected and 10 being the hardest or most difficult to detect. Obviously, for this
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rating system to work, its vital that all team members understand what constitutes a failure. Each potential effect of failure is given a severity, occurrence and detection rating. Those numbers are multiplied to produce a Risk Priority Number (RPN).
Example: One potential failure is that a worker gets his arm cut off in a process - that's a very high severity rating, a 10. The occurrence of that is very low, however, and is given a 1. Detection is obvious, so that also gets a 1. So the RPN is 10 (10 times 1 times 1). Premature die wear is another example of a failure mode. Its a fair severity, but we can catch it before it affects the customer - say it is a 6. But the frequency of seeing that is much higher, maybe also a 6. The ability to detect this type of wear may vary but we assume we have a good maintenance process in place and we give this a 3. So the RPN for premature die wear is 6 times 6 times 3. (i.e)6x6x3=108.
The RPN is an absolute ranking of a system's potential for failure. After several FMEAs are undertaken, the RPNs reveal a clear pecking order for prioritizing corrective actions. The RPN number also serves as a benchmark against which to measure improvements.
5.4.3 Prioritizing, Actions plans
Once the RPN is calculated, the team must develop action plans for correcting, mitigating or eliminating the potential problem. Going through the process of defining possible failure modes and causes of failure gives the team a
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significant head start on recommending action plans. Usually it is just a matter of translating what they've found into specific tasks and assigning responsibility for getting the job done.
5.5 DEFINITIONS
− CAUSE: A Cause is the means by which a particular element of the design or process results in a Failure Mode.
− CRITICAL
CHARACTERISTICS:
Critical
Characteristics
are
Special
Characteristics defined by Ford Motor Company that affect customer safety and/or could result in non-compliance with government regulations and thus require special controls to ensure 100percent compliance.
− CRITICALITY: The Criticality rating is the mathematical product of the Severity(S), and Occurrence(O) ratings. Criticality = (S) × (O). This number is used to place priority on items that require additional quality planning.
− CURRENT CONTROLS: Current Controls (design and process) are the mechanisms that prevent the Cause of the Failure Mode from occurring, or which detect the failure before it reaches the Customer.
− CUSTOMER: Customers are internal and external departments, people, and processes that will be adversely affected by product failure.
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− DETECTION: Detection is an assessment of the likelihood that the Current Controls (design and process) will detect the Cause of the Failure Mode or the Failure Mode itself, thus preventing it from reaching the Customer.
− EFFECT: An Effect is an adverse consequence that the Customer might experience. The Customer could be the next operation, subsequent operations, or the end user.
− FAILURE MODE: Failure Modes are sometimes described as categories of failure. A potential Failure Mode describes the way in which a product or process could fail to perform its desired function (design intent or performance requirements) as described by the needs, wants, and expectations of the internal and external Customers.
− FMEA ELEMENT: FMEA elements are identified or analyzed in the FMEA process. Common examples are Functions, Failure Modes, Causes, Effects, Controls, and Actions. FMEA elements appear as column headings in the output form.
− FUNCTION: A Function could be any intended purpose of a product or process. FMEA functions are best described in verb-noun format with engineering specifications.
− OCCURENCE: Occurrence is an assessment of the likelihood that a particular Cause will happen and result in the Failure Mode during the intended life and use of the product.
− RISK PRIORITY NUMBER: The Risk Priority Number is a mathematical product of the numerical Severity(S), Occurrence(O), and Detection(D) ratings.
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RPN = (S) ´ (O) ´ (D). This number is used to place priority on items that require additional quality planning.
− SEVERITY: Severity is an assessment of how serious the Effect of the potential Failure Mode is on the Customer.
− SIGNIFICANT CHARECTERISTICS: Significant Characteristics are Special Characteristics defined by Ford Motor Company as characteristics that significantly affect customer satisfaction and require quality planning to ensure acceptable levels of capability.
− SPECIAL PROCESS CHARECTERISTICS: Special Process Characteristics are process characteristics for which variation must be controlled to some target value to ensure that variation in a Special Product Characteristic is maintained to its target value during manufacturing and assembly.
− SPECIAL PRODUCT CHARECTERISTICS: Special Product Characteristics are product characteristics for which reasonably anticipated variation could significantly affect a product’s safety or compliance with governmental standards or regulations, or is likely to significantly affect customer satisfaction with a product.
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Figure 5.1 FMEA Process Flow
Figure 5.1 is referred from “Construction planning, equipment and methods” by R.C.Peurifoy, W.V.Ledpettre, McGrawhill, Newyork, 1986.
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5.6 APPLICATION OF FMEA
Let us consider a Tower Crane as an example for FMEA process. The details of a Tower Crane that has been used in a month for various types of projects are as follows.
5.6.1 Functions of the Tower cranes.
Tower cranes are used in various construction projects of high buildings,bridges,cooling towers, Television towers or Power plants.
The construction of the tower crane is such that it can work and then dismantled in restricted space.
The tower has a truss structure welded from angle bars and channels.
Tower extension pieces are available to increase the height as per the requirement.
Ladders are provided inside the whole height of the tower.
An operators cabin is provided so as to enable full view.
Jib is attached to the last highest section of the tower.
Two sections of the jib, opposite to one another, are provided, one is saddle jib and another is counter weight jib. A saddle moves horizontally on rails provided on the saddle jib and is controlled from the hook block.
The upper portion of the tower is fixed on the slewing head.
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5.6.2. Failures of the Tower crane
Due to more stresses beyond its rated capacity as determined by the manufacturer or builder
It occurs due to improper inspection done on blocks, shackles, sheaves, wire rope connectors (etc).
Adjustments and repairs to tower cranes not done by competent, designated persons.
Improper footings provided for tower cranes also cause failure.
Power-controlled lowering devices is not capable of handling rated loads and speeds in such a way that it is also not providing precision lowering and reduce demands on the brake loads.
If the cabs and remote control stations for tower crane are not adequately ventilated.
If automatic trolley brake is not available in case of trolley breakage.
Due to hydraulic line failure.
Failure occurs due to Tower cranes operated with the wind speed is greater than 30 miles per hour which is more than the average speed.
Operation of a crane done without counterweight.
Improper not well trained operators.
5.6.3. Effects of the failure
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More stresses beyond the rated capacity may tilt or Damage the crane
Improper inspection leads to sudden unexpected failures.
Adjustments and repair to tower cranes not done by designated persons may again leads to the repair or failure of the crane.
Cabs and remote control station shall protect from falling objects and materials and also from the elements.
Cab windows not constructed with transparent safety glazing material cause invisibility to the operator.
If automatic trolley break is not available in case of trolley rope breakage then non-stopping, uncontrollable movement occurs.
If the tower cranes operated when the wind speed is greater than 30 miles per hour will cause uncontrollable operation.
Operation of a crane without counterweighgt trolley was found
to be
faulty.(Not running smoothly).
5.6.4. Severity of failures in cranes.
Works get delayed.
Sometimes Human life may also severely gets affected.
Repair work of tower crane not done by designated persons may cause heavy loss of money if it again gets repaired.
Uncontrollable operation of crane due to high wind speed affects human life sometimes.
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Improper protection in the cabs and remote control station may severely affect the human life.
5.6.5. Causes for the failures.
Improper inspection.
Improper trained operators.
Not selecting well designated and more experienced persons.
Improper maintenance of every individual parts of a crane.
Improper footings provided on tower cranes.
5.6.6. Determination of frequency of failures. Determine the
Type of failure that occurs most likely.
Periodically what type of failure occurs in the Crane.
Its severity on the crane.
5.6.7. Risk priority number
Rate the occurrence of failure, (ie) how frequently the failure occurs. Accordingly detection scale is formed with one being the easiest or most detected and 10 being the hardest or most difficult to detect. Obviously for this rating system to work, It is vital that all team members understand what constitutes a failure. Each potential effect of failure is given a severity, Occurrence and
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detection rating. Those numbers are multiplied to produce a Risk Priority Number (RPN). Table 5.1 shows the risk priority number for Tower Crane Therefore to find out the value of
RISK PRIORITY NUMBER (RPN) = DETECTION SCALE NO X SEVERITY SCALE NO X OCCURRENCE
SCALE
NO.
Table 5.1 RPN VALUE FOR TOWER CRANE S.No
Parameter
1 2
Improper footings Adjustments and repairs not done by designated persons. Stresses beyond its rated capacity Improper inspection cabs and remote control stations not adequately ventilated. Tower cranes operated with wind speed more than the average speed Operation of crane done without counterweight automatic trolley brake not available Power-controlled lowering devices not capable of handling rated loads and speeds Improperly trained operator
3 4 5
6
7 8 9
10
Detection Scale(D) 1 2
Severity Scale(S) 5 6
Occurrence Scale(O) 2 7
RPN (DXSXO) 10 84
3
8
6
144
4 5
10 4
5 8
200 160
6
9
1
54
7
3
9
189
8
1
4
32
9
7
3
189
10
2
10
200
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It is observed that in a tower crane risk priority number is more for improper inspection and improperly trained operator.
5.7
FUNCTIONS OF EARTH MOVING EQUIPMENTS.
a) Loosening the material to put into a workable state. b) Digging the material to start the move from its original location. c) Moving the material from its original location to deposit point. d) Dumping the material at its place for deposit. e) Working on the material to put it into final specified condition at its place of use.
As an example like tower crane functions, failures, effects, severity and occurrence details of a motor grader fitted to a vehicle for earth moving equipments.
5.7.1
Functions of a motor grader.
a) It is a piece of equipments used to move earth (or) other loose material. b) Its function is generally to plane, mold or grade the material. c) It is working to a given line (or) contour. d) It is especially useful because of its blade that can be held in various positions. e) The standard blade is 10 to 14 feet in length.
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f) Cutting force at the grounds surface is applied toward the leading end and along the length of the blade. g) The turning radius is about 20 feet. h) It is used for shaping and final grading of the total roadway width. i) It also cuts the base for the road surface but also the side slopes, back slopes and V-shaped drainage ditches along the roadway. j) With the attachment of a short blade, a shallow box-shaped trench can be dug by the motor grader.
5.7.2
Failures of the motor grader.
a) If the blade slope does not agree with the setting b) Improper scarifier teeth c) The blade gets braked. If it allows to cut below a certain level. d) If the speed of forward travel is not slow and constant. e) Improper maintenance of graders. f) Due to non-uniformity, irregularity and not straight forwardness of the operation, improper efficiency in operation takes place. g) Improper not well trained operators. h) Adjustments and repairs to graders not done by designated persons. i) If improper or old motor graders are used not having automatic blade controls in it. j) It occurs due to improper inspection and lubrication work in it. 5.7.3
Effects of the failure.
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a) Improper inspection leads to sudden unexpected failures. b) Improper scarifier teeth leads to improper cutting. c) Improper efficiency in operation gives a bad result on the work. d) Improper maintenance on grader units will give a sudden failure to the equipment. e) If the speed of travel is not constant leads to improper work.
5.7.4
Severity of failures in motor graders.
a) Work gets delayed. b) Improper work done. c) Sometimes human life may also gets affected. d) Repair work not done by designated persons may cause heavy loss of money. e) Improper protection due to breakage of blade may severely affect the human life.
5.7.5
Causes for the failures.
a) Not constant speed of travel in operation. b) Improper scarifier teeth. c) Improper trained operators. d) Not selecting well designated and more experienced persons.
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e) Improper maintenance on grader units. f) Improper inspection.
5.7.6
Risk Priority Number
According to this method the failures of earth moving equipment, motor grader have been rated from 1 to 10 under detection, severity, and occurrence scale. Table 5.2 shows the risk priority number for motor grader
TABLE 5.2 RPN VALUE FOR MOTOR GRADERS S.No
Parameter
1
Abnormal setting of the slope of the blade Improper scarifier teeth If blade cuts above a certain level Speed is not slow and constant Improper maintenance of graders Improper efficiency Improperly trained operators Adjustments and repairs not done by designated persons Old motor graders without automatic blade Improper inspection and lubrication
2 3 4 5 6 7 8
9
10
Detection Scale(D) 8
Severity Scale(S) 5
Occurrence RPN Scale(O) (DXSXO) 2 80
3 1
3 2
3 10
300 20
2
7
8
48
5
4
1
180
7 6
1 10
6 9
36 540
4
8
5
160
9
6
7
378
10
9
4
360
It is observed that in a motor grader risk priority number is more for improperly trained operators, which indicates that the operator must be trained properly.
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5.8
CONCRETE MIXING EQUIPMENTS
Concrete mixers, functions, failures, causes and severity details are to be taken as an example for concrete mixing equipments.
5.8.1
Functions of the concrete mixers.
a) Concrete mixers are used for concreting the materials to the building construction where it requires. b) The materials are mixed freely in a rotating drum with rapidly secured vanes rotating independently of the drum. c) The mixers are discharged by tripping or tilting the drum or, if it is fixed horizontally by inserting a discharge tray into it. d) It is necessary to tilt and lift the empty drum several times, watching attentively it motions, examining the pneumatic drive connections and listening to any unusual knocks or impacts in individual units. e) When the drum is loaded from a skip, see that the skip is rapidly and completely emptied. f) If the concrete mix is conveyed by cyclic action vehicles, the vehicles should be brought uninterruptedly to the point of loading, their numbers and capacity corresponding to the output of the mixing equipment.
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5.8.2 Failures of the concrete mixers. It occurs due to a) Not inspecting the lubrication points. b) Improper packing of the cap oilers. c) Not checking whether adjustment done on all the mechanisms. mechanisms. d) Improperly trained operators. e) Not examining the bolt and articulated joints of a mixing machine. machine. f) Improper checking to the skip after it is completely emptied. g) Not stopping the machine even though the bearings are found found to be over heated (when they are too hot to be touched). h) For ready-mix – concrete the drum must rotate at a speed of 4.5 to 6 rpm. If the drum is loaded with dry concrete it must be started only 1012 min before unloading. Improper speed and time leads to failure. i) Adjustments and repairs not done by competent, designated persons. j) Pouring more material than the rated capacity of the concrete mixers. 5.8.3
Effects of the failure a)
Pouring more material than the rated capacity of the concrete mixers may tilt or damage the mixer.
b)
Adjustments and repairs not done by designated persons may again leads to the repair. c)
Not stopping the machine even though the bearing are found to be overheated will some times affect the human life.
d)
Improper speed and time leads to uncontrollable operation.
e)
Improper inspection leads to sudden unexpected failures.
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f)
Improper maintenance on bolt and articulated joints will leads to sudden failures.
5.8.4
Severity of failures in concrete mixers. a)
Sometimes human life gets affected.
b)
Improper speed and time leads to improper i mproper operation.
c)
Repair work not done by skilled persons may cause heavy loss of money.
d)
5.8.5
Works get delayed.
Causes for the failures a)
Improper speed and time.
b)
Improper maintenance on every individual parts of the mixer.
c)
Improper inspection.
d)
Improper trained operators.
e)
Pouring more material than the rated capacity of the mixer.
f)
Not selecting well designated and most most experienced persons.
5.8.6
Risk Priority Number According to this method the failures of concrete
mixing equipment
Concrete mixer have been rated from 1 to 10 under detection, severity, occurrence scale Figure 5.3 shows the risk priority number for concrete mixer.
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TABLE 5.3 RPN VALUE FOR CONCRETE MIXERS S.No
Parameter
1
Improper inspection on lubrication points Improper packing of 9 the cap oilers.
2
Detection Scale(D) 8
Severity Scale(S) 5
Occurrence RPN Scale(O) (DXSXO) 5 200
6
4
216
3
Improper checking on all the mechanisms
1
2
6
12
4
Improperly trained operators Improper checking to the skip. Not stopping the machine even though bearings are found to be overheated Improper speed and time Adjustments and repairs not done by designated persons Pouring more material than the rated capacity Not examining the bolt and articulated joints of a mixing machine
10
3
9
270
6
4
8
192
7
1
7
49
3
7
1
21
4
8
10
320
5
10
2
100
2
9
3
54
5 6
7 8
9 10
It is observed that in a concrete-mixer risk priority number is more for adjustments and repairs not done by a competent designated person. CHAPTER 6
6.0 SUMMARY AND CONCLUSION OF THIS STUDY
6.1
INTRODUCTION
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Equipment plays a vital role in any construction project and is a major resource for earning profits. Maintenance of equipment lies in the hands of management and its approach towards maintenance practice. It is very important to strike a balance between economical maintenance and utilization of equipment. It is often found that progress of work at construction site suffers because of improper planning and scheduling of equipment for maintenance purpose. Also lack of coordination between Equipment maintenance department and site execution team creates a negative impact on life and out put of equipment. All these problems can be resolved by implementing a systematic management approach which aims at obtaining maximum work out of equipment in conjunction with maintaining its fitness with minimal expenditure.
The advent of new and sophisticated equipments makes its imperative to maintain its working condition to generate optimum output. Newer technology has also paved way for the implementation of annual maintenance contract, so that the contractor gains enough technical know how before he starts maintaining and operating the plant or equipment on his own.
6.2 FINDINGS AND RECOMMENDATIONS
Since the objective of this thesis is to study the maintenance management practices that are currently being followed by large construction company and to identify better practices for effective maintenance management. On reviewing and
lxxxviii
analyzing the approach of two leading construction firms i.e. LARSEN &TOUBRO Ltd. and CONSOLIDATED CONSTRUCTION CONSORTIUM Ltd. both well known for owning large a fleet of equipments, the following recommendations are suggested:
6.2.1
FINDINGS AND CONCLUSIONS
a) Both the companies followed a combination of preventive maintenance and breakdown maintenance. b) On an average ( considering a group of 9 equipments) it is found that utility of L&T was 13.76 percent more than CCCL c) On an average (considering a group of 9 equipments) it is found that total expenditure on maintenance of L&T is 33.14 percent more than that Of CCCL. . d) For maintenance of plants such as hot mix ,batching plant, crushing plant rather than simply relying on preventive maintenance a better option is to go in for a combination of
breakdown (minimum percent), preventive,
predictive(maximum percent) maintenance also known as reliability centered maintenance. e)
From the analysis it is found that L&T are in a better position as compared to CCCL in optimizing equipment utility, usage and total maintenance cost.
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6.2.2
RECOMMENDATIONS
a) Breakdown maintenance should be avoided as far as possible. b) A combination of Preventive maintenance and predictive maintenance will give better results for equipments. c) Reliability centered maintenance should be followed for maintenance of plants. d) Proper manpower planning and maintenance scheduling synchronized with optimum utilization should be aimed at for improving interdepartmental conflicts. e) Need of creating a database for efficient equipment management has become imperative for proper control and monitoring of equipment status at any point of time. f) FEMA can effectively used to find out in advance the failure modes and hence precautionary measures can be taken. g) In a tower crane risk priority number is more for improper inspection and improperly trained operator. h) In a motor grader risk priority number is more for improperly trained operators, which indicates that the operator must be trained properly. i) In a concrete-mixer risk priority number is more for adjustments and repairs not done by a competent designated person. Thus failures vary for each equipment due to RPN value. Thus RPN plays a vital role for each equipment failures.
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6.3
SUGGESTIONS FOR FUTURE RESEARCH Software can be developed to enhance the efficiency of using the Failure
Modes Effects Analysis (FMEA). For the present study only 10 parameters are considered for analyzing the modes and effects of failure. But if software is used for the analysis, more parameters can be used in the analysis thereby level of risk of failure can be reduced and more saving in the cost of maintenance can be achieved.
REFERENCES
1. Campbell .D.H, Construction Equipment Management, Dept. of
Civil
Engineering , University of Waterloo,1974. 2. Chitkara.K.K , construction project management – planning,scheduling,controlling,Tata McGraw-Hill, New Delhi,1997. 3. Deodhar.S.V,
construction
equipment
and
job
planning
–
khanna
publishers,2nd edition 2001. 4. Havers John A, Stubbs Jr.Frank W., Handbook of Heavy Construction ,McGrawhill book company,2nd Edition-1971. 5. E.D.Hester, World Heavy Construction Equipment, Study No.1176, Cleveland, Ohio, The Fredonia Group,1999, 6. Indian Concrete Journal- Aug 1992,Pg 14-54 by Lynn Bandburg. 7. Peurifoy.R.C, Ledpettre.W.V, Construction planning ,equipment and methods,McGrawhill,New York,1986.
