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A Total Productive Maintenance (TPM) Approach To Improve Overall Equipment Efficiency Document Transcript
International Journal of Modern Engineering Research (IJMER) www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4383-4386 ISSN: 2249-6645 A Total Productive Maintenance (TPM) Approach To Improve Overall Equipment Efficiency Hemant Singh Rajput1, Pratesh Jayaswal2 1 (Mechanical, M.I.T.S. /R.G.P.V., India) 2 (Department of Mechanical Engineering, R.G.P.V. University, India)ABSTRACT:Good maintenance is fundamental to Together by a combination of good working practices,productive manufacturing system. Total Productive team working,Maintenance (TPM) is an alternative approach to And continuous improvement . TPM isequipment maintenance that seeks to achieve zero intended to bring both functions (production andbreakdowns and zero defects. TPM is an approach to keep maintenance) together by a combination of good workingthe current plant and equipment at its higher productive practices, team working and continuous improvement .level through cooperation of all areas of organization. Inthis paper the selected machines were carefully studied in II. PILLARES OF TPMan industry. Data for past have been analyzed and results The Japan Institute of Plant Maintenance proposeachieved are quite encouraging in terms of motivated the introduction of TPM program is based on theemployees, improvement in overall equipment effectiveness implementation of a series 8 pillars of TPM in a systematic(OEE) and reduction in no. of accidents on shop floor. The way to optimize plant and equipment efficiency by cratinganalysis has revealed that there are 98% good perfect relationship between man and equipment. Thecomponents, 2% rework losses, where the nine most diagram below represents a common structure of TPM.common causes were identified for the machine stoppages. Figure 1The OEE was 67% and the six big losses represent 35% • Autonomous Maintenance / Jishu Hozen.loss of the product time. Based on the findings, it was • Focused Improvement /Kobestu Kaizen.recommended to implement a TPM to improve the OEE of • Planned Maintenance.the plant. • Quality Maintenance. • Training.Keywords: Manufacturing performance, overall • Office TPM.equipment effectiveness implementation, planning, • Safety, Health and Environment.training, TPM, etc. • Initial Flow Control. I. INTRODUCTION In this competitive world total elimination ofwaste is necessary for the survival of the organization. Thewastes generated due to the failure shutdown of facilitiesthat have been built, with huge investment and also wastesuch as defective products should be absolutelyeliminated. In a manufacturing scenario, the desirableproductivity, cost, inventory, quality and delivery alldepend on the efficient functioning of the company’sfacilities. The philosophies like, total quality management Fig. 1 Pillars of TPM(TQM), just in time (JIT), flexible manufacturing systems(FMS),etc. have led to a comprehensive maintenance III. AUTONOMOUS MAINTENANCE/JISHUtechnique known as total productive maintenance (TPM) HOZAN. Hartman defines TPM as “Total Productive Japanese name of autonomous maintenance isMaintenance permanently improves the overall JISHU HOZEN. This activity is geared towardseffectiveness of equipment with the active involvement of developing operators to be able to take care of smalloperators” . The aim of TPM to reduce maintenance tasks, thus freeing up the skilled maintenance The six major equipment losses, to zero, have people to spend time on more value added activity andbeen recognized as necessary for corporate survival. TPM technical repairs. The operators are responsible for upkeepis a unique Japanese system of plant management, of their equipment to prevent it from deteriorating.developed from preventive maintenance concept. This Autonomous maintenance includes any activity performedapproach emphasizes the role of teamwork, small group by the production department that has a maintenanceactivities, and the participation of all employees to function and is intended to keep the plant operatingaccomplish equipment improvement objectives . It efficiently and stable in order to meet production plans .challenges a sense of joint responsibility between Autonomous maintenance is closely linked with focusedoperators and maintenance workers, not only to keep the improvement in that both support equipment restorationmachines running smoothly, but also to extend and and sustaining basic equipment conditions .optimize their overall performance . It is also defined Following policies are adopted for developing JISHUas, bringing both functions (production and maintenance) HOZEN: www.ijmer.com 4383 | Page
International Journal of Modern Engineering Research (IJMER) www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4383-4386 ISSN: 2249-6645• Uninterrupted operation of equipment’s. The first two losses are known as down time loss• Flexible operators to operate and maintain other and are used to calculate availability of a machine. The equipment’s. third and fourth are speed losses that determine the• Eliminating the defects at source through active performance efficiency and the final two losses are employee participation. considered to be losses due to defects in the products. OEE• Stepwise implementation of JH activities. is measured in terms of these six losses, which are function of availability, performance rate and quality rateIV. FOCUSSED IMPROVEMENT/ KAIZAN of the machine, production line or factory . And Focused improvement includes all activities that claims, increasing productivity, reducing costs, shrinksmaximize the overall effectiveness of equipment, inventory, decreasing accidents and promoting employeeprocesses and plants through elimination of losses . It involvement . Suzuki cites Productivity, Quality,includes identification, quantification and elimination of Costs, Delivery, Safety and Morale (PQCDSM),losses that affect productivity, quality, performance, etc. improvement for early TPM implantation.OEE is a key metric of focused improvement. Focusedimprovement is characterized by a drive for zero lossesmeaning continuous improvement effort to eliminate anyeffectiveness losses. Kaizen is a Japanese word forimprovement. According to Kaizen, it is a fact that everyemployee of the company is capable of improving hiswork and the method of working. Kaizen forms anessential part of TPM. V. OEE AND SIX MAJOR LOSSES The literature reveals that no standard exists forcalculation of OEE. The OEE calculation is quite generaland can be applied to any manufacturing organization .OEE is a measurement used to determine how efficiently amachine is running. Though the definition implies thatOEE is the measure of a particular machine, but it can alsobe used to measure efficiency of product lines, sections ofa plant or even the entire plant. Philip Godfrey  notesthat the effective operation of individual pieces ofproduction equipment, assembly lines or whole factory isdependent on the three factors of OEE . OEE is themost effective measure for driving plant improvement. Itcontinuously focuses the plant on the concept of zero-waste . Unless careful monitoring occurs, the reducedcapacity goes unnoticed or is accepted as normal. OEE canbe considered to combine the operation, maintenance andmanagement of manufacturing equipment and resources. The losses are divided into six major categories, whichaffect the overall performance of the equipment namely:1. Equipment failures/breakdown losses are the time The overall performance of equipment’s can be losses and quantity losses caused by defective enhanced by identifying and eliminating the root causes. products. OEE is used as a tool to measure the effectiveness of2. Set-up and adjustment losses are defined as time equipment’s to know the current condition. It helps to losses resulting from downtime and defective identify the areas of improvement required in terms of products that occur when production of one item ends availability, performance efficiency and quality rate of and the equipment is adjusted to meet the products classifying them into six major losses, as requirements of another item. identified by Nakajima in the OEE model . These six3. Idling and minor stop losses occur when the major losses are overcome by the Focused Equipment production is interrupted by a temporary malfunction Improvement (FEI) and Autonomous Maintenance (AM) or when a machine is idling. activities of TPM, (Refer fig. 2). These activities will be4. Reduced speed losses refer to the difference between more effective if carried, in small groups or teams, which equipment design speed and actual operating speed. are more active, dynamic, self-motivated and also5. Reduced yield losses occur during the early stages of increasing one’s-self-confidence of participants. production from machine start up to stabilization.6. Quality defects and reworks are losses in quality VI. PROBLEM STATEMENT caused by malfunctioning of production equipment. Model Machine selected for the implementation of TPM is Shot Peening Machine for the following reasons. www.ijmer.com 4384 | Page
International Journal of Modern Engineering Research (IJMER) www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4383-4386 ISSN: 2249-6645 • Poor performance among the other shot -peening TCT - theoretical cycle time, machines PA - processed amount, and • Oldest machine OT - operating time. • Dusty and dark atmosphere Targeted capacity of shot peening machine is 22 MT/hr. • Poor house-keeping Theoretical cycle time is 2.72min./MT and • Poor safety Processed Amount (PA) 11000 MT/ month (approx.) Performance efficiency (PE) = 2.72 × 11000/627.5 × 100 VII. OBJECTIVES = 79.4% The objectives of this case study were, PE = Speed efficiency × Rate efficiency • Improve equipment reliability and maintainability. Where, • To cultivate the equipment-related expertise among Speed efficiency = ICT /ACT operators. ICT - Ideal cycle time and • Maximize OEE, through total employee involvement. ACT - Actual cycle time • Create an enthusiastic work environment. Rate efficiency = (PA × AT) /OT, Where,VIII. PROPOSED IMPLEMENTATION PLAN FOR TPM AT is Actual time. These losses occur due to machine The following plan were used for the implementation of running at slower speed than the designed speed because TPM activities, of vibration and improper maintenance, also due to idle • Initial cleaning and minor stoppage etc. • Listing and classification of abnormalities Rate of Quality products = ((PA-DA) /PA) × 100 • Why-Why Analysis • Kaizen = (11000-220)/11000 × 100 = 98%. • Jishu Hozan Defected Amount = 2% of PA = 440 MT (app) • Safety OEE on Shot Peening Machine = Availability × IX. DATA ANALYSIS Performance Efficiency × Rate of Quality First of all out of the whole plant process equipment’s bottleneck equipment is identified and was = 0.8715 × 0.794 × 0.98 = 66.4% decided to consider this for TPM implementation study. Major losses during the production on this equipment were pointed out using a time study. The study was carried out in all three shifts for two continuous hours in each shift. Two persons standing on either side of the line with the stop watches noted down whenever there was a stop or any other situation occurring, which led to idle or stoppage time on equipment. Three days continuously the study was conducted and finally average of all these readings were calculated in order to decide the final values of various losses on respective equipment. According to study, small interruptions were the biggest contributors to the time losses. So looking into the type of losses it seems that there is lot of scope for improvement in the profitability after implementation of TPM. Calculation of OEE: Working days in a month = 30 × 24 hrs. Planned down time in a month = 10 hrs. Setup adjustment losses per day (Which includes material not available, Job setting, rework) = 1.75hrs Setup adjustment losses per month = 52.5 hrs. X. CONCLUSION Breakdown time in hrs. Per day = 1 hrs. The process of recording information must Breakdown time per month = 30 hrs. remain simple, but effective for future data analysis .if Total down time per month = (Planned down time + setup provisions were made to highlight such problems and adjustment losses + breakdown time)/month = 10 + 52.5 + possible causes, then it may lead to the correction of 30 = 92.5 hrs. /month common problems such as breakdowns and rework. Operating time per month = Running Time - Total down Ultimately if possible, the aim is to eliminate such causes. time = 720 hrs. -92.5 hrs. = 627.5 hrs. Information provided by the trend analysis can provide a Availability = (loading Time – Down Time)/Loading time basis for forming- long-term plans. The maintenance = (720-92.5)/720 = 87.15% department can plan spending requirements by using Performance efficiency (PE) is calculated as historical information to state the return on investments by PE = ((TCT×PA)/OT) ×100 contributing to the annual business plan of the company. Where, Therefore if the world-class performance of 85%OEE was www.ijmer.com 4385 | Page
International Journal of Modern Engineering Research (IJMER) www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4383-4386 ISSN: 2249-6645achieved then 20%increase in OEE would have represent  Philip Godfrey, “Overall Equipment Effectiveness”enhance the annual earning .To achieve this target efficient Manufacturing Engineering, 81(3), 2002, 109-112.maintenance is necessary, in order to establish autonomous  ckone. K. E, Schroder, Total Productivemaintenance teams, better Communication and team- work Maintenance: A contextual View, Journal ofmust be promoted. It is essential that the company devices Operations Management, 17, 1999, 123-144.an efficient data recording systems, so that up-to date and  Nakajima, S. Introduction to TPM: Total Productiveaccurate information will be available to the management Maintenance, (Productivity Press, Cambridge, MA,Information provided by the trend analysis can provide a 1989).basis for forming- long-term plans.  Lungberg. O, Measurement of overall equipment effectiveness as a basis for TPM activities, REFERENCES International Journal of Operation. & Production Hartman. E, “Successfully Installing TPM in a Non- Management, 18(5), 1998, 495-507. Japanese Plant”, (Pittsburgh, PA, TPM Press, Inc.,  Venkatesh J, An Introduction to total productive 1992). Maintenance, 2005. Bamber, C. J, Sharp, J. M, Hides. M. T, Factors  Suzuki, T., TPM in Process Industries, (Portland OR, affecting Successful Implementation of Total Productivity Press, 1994) Productive Maintenance: A UK Manufacturing Case  Anil Badiger, S., Gandhinathan, R., A Literature study Perspective, Journal of Quality in Maintenance Overview on Overall Equipment Effectiveness Engineering, Vol.5, 3, 1999, 162-181. (OEE), Journal on Manufacturing Engineering, 5(3), Bulent Dal, Phil Tugwell, and Richard Greatbanks, 2006, 49-56. “Overall equipment effectiveness as a measure of  Kunio Shirose, TPM for Operators, (Norman Bodek, operational improvement A practical analysis”, Productivity, 1992). International Journal of Operations & Production  Leflar. J, Practical TPM, (Portland OR, Productivity Management, 20(12), 2000, 1488-1502. Press, 2001). Debadyuti Das. “Total Productive maintenance  Anil Badiger, S., Gandhinathan, R., Impact of (TPM): A comprehensive tool for achieving Focused Improvement and Autonomous excellence in operations system – A case study”, Maintenance on OEE: A study, The ICFAI Journal Industrial Engineering Journal 30 (10), 15, 2001. of Operations Management, 5(2) 2006, 23-34. Cooke, F. L., Implementing TPM in plant  Brave. S.B, Birajdar. H.S, Bhongade. A.S, and maintenance: some organizational barriers, Hemant Chaudhari, Application of Total Productive International Journal of Quality and Reliability Maintenance (TPM) to vertical boring machine, Management, 17(9), 2000, 1003-1016. Industrial Engineering Journal, 33(7), 2004 22-27. Thomas R. Pomorski, Total Productive Maintenance  Tajiri. M, Gotoh. F, TPM Implementation -A (TPM) Concepts and Literature Review, (Brooks Japanese Approach, (Mc Graw Hill, New York, Automation, Inc.2004). 1992). www.ijmer.com 4386 | Page