The origin of TPM can be traced back to 1951 when preventive maintenance was first introduced in Japan. The Japanese took the concepts and techniques of preventive maintenance from the U.S.A. The induction of preventive maintenance from the U.S.A. heralded the modernization of plant maintenance in Japan. Nippondenso Company Limited first introduced plant-wide preventive maintenance in 1960. This was the usual form of preventThe origin of TPM can be traced back to 1951 when preventive maintenance was first introduced in Japan. The Japanese took the concepts and techniques of preventive maintenance from the U.S.A. The induction of preventive maintenance from the U.S.A. heralded the modernization of plant maintenance in Japan.

These tasks are aimed at maintenance prevention (MP). Thus preventive maintenance together with MP and maintainability improvement (MI) activities gave birth to productive maintenance (PM). The aim of productive maintenance is, therefore, the maximization of plant and equipment effectiveness in the pursuit of economic effectiveness and achievement of optimum life cycle cost of production equipment. This was the origin of the second important feature of TPM, which involves activities to maximize equipment effectiveness.

Based on the above development, Nippondenso evolved TPM between 1969 and 1971, and it was awarded the 1971 Distinguished Plant Prize (PM Prize) for the development and effective implementation of TPM by the Japanese Institute of Plant Engineers (JIPE). Thereafter, the formal definition of TPM was enunciated by JIPE in 1971.

MOTIVATIONS AND IDENTIFYING CHARACTERISTIC OF TPM

Takahashi has identified three specific motives for the advocation and subsequent adoption of TPM in Japan . These three motives are as follows:

 1. Adoption of the life cycle approach for improving the overall performance of production equipment.

 2. Improving productivity through a highly motivated workforce, which can be achieved through job enlargement in which all workers are given a range of challenging jobs in order to develop their skills at different crafts.

3. The use of voluntary small group activity for identifying the likely cause and frequency of failure of critical equipment, possible plant and equipment modifications, which will result in significant savings, and efforts to fully utilize existing equipment through improved availability.

Two specific parts of the first motive are as follows:

 i) Pursuit of economic life cycle cost of physical assets, which must include building in of reliability and maintainability features and the extension of the useful life of the assets, and since TPM deals primarily with production equipment and is used in manufacturing industries, such assets are plant and machinery, and

 ii) Improving the overall performance of plant and machinery, which should also take into account the effective use of such production equipment through the minimization of losses not only due to breakdowns, but also due to poor quality and losses due to set-up, adjustment, idling and minor stoppages of the equipment and equipment operating at reduced speeds.

Wireman, in his book on TPM, explains the first two clauses of the formal definition of TPM, namely maximizing equipment effectiveness and establishment of a total system of PM covering the whole life of equipment, as ensuring equipment capacity and implementing a programme of maintenance for the entire life of the equipment . He goes on to state that ensuring equipment capacity implies efforts directed at ensuring that the equipment performs to its specifications — ‘operates at its design speed, produces at the design rate and results in quality product at these speeds and rates’. This implies efforts aimed at the maximization of equipment utilization (and not just the maximization of equipment availability), and there are six significant causes of reduction of equipment utilization. These are as follows:

 1. Losses due to ineffective maintenance, and these, in TPM terminology, are called breakdown losses.

2. Setup and adjustment losses.

3. Loses due to idling and minor stoppages of equipment.

 4. Loss due to operation at reduced speed, or at less than full (design) load — this Wireman calls ‘reduced capacity loss’ .

 5. Losses due to poor product quality — due to defects in process and production of defective items.

 6. Loss due to reduced yield from the startup of the equipment to the point of stable production — and this Wireman calls ‘startup/restart loss’

The reduction of equipment utilization has three constituents, which have to do with the availability of the equipment, the rate at which the equipment is performing, and the product quality performance of the production equipment (this, in TPM literature, is called the ‘quality rate’, in keeping with the performance rate). Thus the overall equipment effectiveness has three constituents, namely, availability, performance rate, and quality rate and

 overall equipment effectiveness = availability × performance rate × quality rate

i) Loading time is the available time on the equipment for production/productive work. This is the total time available minus the necessary time for planned or essential activities, such as time lost due to meetings, scheduled tea/coffee breaks or precautionary rest periods, and also breaks in production schedule or planned production stoppages for planned/preventive maintenance work, and, on rare occasions, scheduled production stoppages for non-maintenance reasons.

 ii) Operation time is loading time minus the downtime, or the time the machine is down for reasons other than given above under (i). Such downtime includes time lost due to equipment breakdowns, setup of equipment, tools, dies and accessories, and adjustments to the equipment. These adjustments are generally carried out by operators, and take less than 10 minutes.

iii) Net operation time is the time the equipment or the machine is operated at its design speed, at the design rate of production, or at the design load. The time lost due to idling and minor stoppages of the machine, and operating it at a reduced speed or at a reduced rate of production is subtracted from the operation time to get the net operation time. The term design load has also been included to take account of process plant equipment, which are either derated and/or operated at low loads for various reasons. An example of this would be a 210 MW thermal power unit being operated at 150 MW because two out of six pulverizers are down. In thermal power plant terminology, such outages are called partial outages.

 iv) Value-added operation time is the net operating time during which actual value addition is carried out. This is obtained by subtracting the total estimated time for rework of defective/nonconforming products from the net operation time. Thus the time required to make up for the quality losses is subtracted from the net operation time to get the value-added operation time.

CHRONIC AND SPORADIC LOSSES

Chronic is used to refer to an undesirable condition, or phenomenon, which is either deep seated and continued over a long time, or occurs repeatedly over a long period of time. As opposed to this, a sudden, or an unexpected, occurrence, which occurs rarely, is referred to as sporadic.

RELATIONSHIP BETWEEN TPM, TERO-TECHNOLOGY AND LOGISTICS

Terotechnology (developed in UK), logistics (in USA) and TPM (in Japan) have the same goals. Terotechnology as per BSI is a combination of management, financial, engineering and other practices applied to physical assets in pursuit of economic life cycle costs (LCC). Its practice is concerned with the specification and design for reliability and maintainability of plant and machinery, equipment, buildings and structures with their installation, commissioning, maintenance modification and replacement with feed back of information on design performance and costs.

TPM aims to maximise equipment effectiveness. In fact this is same as terotechnology’s goal of attaining an economic life cycle cost.

 Logistics is an old military term referring to support to front line through procurement, storage, transportation and maintenance of manufactured goods and systems. In current methods, logistics consists of LCC, reliability engineering and maintenance engineering. Thus the goal of TPM, tero-technology and logistics is same as goal of LCC and they differ in terms of pre-use target location and responsibility.

Objectives or Goals of TPM

 (a) To maximise overall plant efficiency.

(b) To maximise overall equipment effectiveness (OEE), i.e. availability, performance and output.

 (c) To achieve zero defect.

 (d) To achieve zero breakdown.

 (e) To achieve total involvement, i.e. participation of all departments and sections, including planning, purchase and user of the equipment (i.e. the production department).

 (f) To improve the overall general environment and working conditions of the plant.

 (g) To boost the morale of the employees by inculcating the sense of pride in them.

Preventive, Corrective Maintenance and Maintenance Prevention for Controlling Deterioration of Equipment

Preventive maintenance (PM) is comparable to preventive medicine; following Figure  shows the relationship. Daily equipment maintenance serves the same purpose. By diligently lubrication, cleaning and performing adjustments and conducting inspection deterioration can be prevented and potential equipment failures (disease) averted. Thus PM decreases number of breakdowns and inevitably increases life span.

Category	Start Up Fail	Chance Failure	Wear Out Failure
Cause	Design/Manufacturing errors	Operational errors	Wear out
Counter measures	Trail seen at acceptance and start up control	Proper operation	Preventive and maitainability improvement

Preventive maintenance alone cannot eliminate breakdowns. Figure Shows life span characteristic curve or Machine Life Cycle (MLC) or bathtub curve of equipment. (For detailed understanding of MLC curve refer Unit 6.) When the equipment is new there will be heavy failure rate (early failure period) which eventually drops and levels off. The failure rate stabilizes to a certain level for a long period of time (accidental failure period). Finally equipment approaches the end of useful life, the failure rate increases once again (Wear-out failure period).

Causes of early failure are design and maintenance errors. So to combat them, the design department must conduct test runs at early stage. Furthermore maintainability improvement should be pursued to discover and treat weakness in design and manufacturing.

Accidental failures are caused primarily by operator errors. Hence most efficient counter measure is to ensure that operators use equipment properly. Wear out failures can be reduced and life span extends by preventive maintenance and maintainability improvement (Through changes in design).

Maintenance prevention is an effective counter measure for all three types of breakdowns. A maintenance free design of equipment must be incorporated at planning stage to prevent early period, accidental and wear-out failures.

THE EIGHT PILLARS OF TPM

The eight pillars are :

A) Kobetsukaizen

Kobetsukaizen, popularly known as Kaizen, means continuous improvement is effected by eliminating various losses that occur in the production and productivity due to human negligence or ignorance in maintaining equipment and machinery properly or maintaining quality of material, tools and other auxiliary items. A detailed discussion on various types of Kaizen is given at the end of this unit. The objective of Kaizen can be stated concisely as

Objective • To maximise the overall effectiveness of equipment, process, and the plant by elimination of all losses through small group activities.

 (b) Safety and Hygiene

Safety and Hygiene (Autonomous System)

 Objective

 • To achieve pleasant working environment.

 • To achieve zero accident.

• To provide safe working conditions and work place.

(C) Office Administration.

Objective

• The objective of this pillar is keep the workmen free from the tensions due administrative problems Explanation The implementation of TPM should also include the administrative part that indirectly influences the job. The planning work, logistics and spare parts management, information flow and wage administration etc will indirectly affect the work of the operators of maintenance.

 (d) Jishuhozen

Objective • To achieve zero equipment failure and zero product defects through the Autonomous Maintenance Activities. Definition Jishu-Hozen can be defined as carrying out initial or basic maintenance of equipment by the operators themselves and informing of the potential of major breakdown. The concept of JISHU-HOZEN lies in the fact that ‘A mother is the best judge regarding the health of her kid than an outsider’. So also the person who works on certain machine knows better about its condition and performance. Thence the basic maintenance work is assigned to the operators of that machinery. Steps (a) Initial cleaning. (b) Taking counter measure at the source of the problem. (c) Inspection. (d) Cleaning, lubrication, greasing, tightening, etc. (e) Systematise autonomous maintenance. (f) Practice full autonomous management. Explanation Establish standard method and time for cleaning, lubricating and tightening of nuts and other loose parts so that minimum time is consumed in these activities.

(e) Education and Development

Objectives

• To disseminate maintenance and engineering know how.

• To eliminate equipment failure, product defects and accidents resulted due to ignorance and lack of skill.

 • To train each and every maintenance personnel in their respective jobs.

 • To develop multi-skill workforce. How to Achieve These can be achieved through :

 (a) Identifying training requirements for each individual in various skills.

(b) Arranging skill enhancement training programmes.

(c) Assessing the effectiveness of training schemes.

(d) Apprising the maintenance personnel of the various reasons for failure and breakdowns, defects in products, low quality of products and reasons for accidents.

 (e) Engineering and maintenance people handle training, emphasizing practical knowledge about real machine past failures.

 (f) The relationship between failures and improper operating procedures and poor maintenance is stressed.

(f) Maintenance Prevention

This maintenance consists of preventive maintenance and maintenance prevention techniques to improve mean time between failures (MTBF). To improve operating time the following six big losses are reduced. (a) Equipment failures (b) Set up adjustments (c) Defectives (d) Yield loss (e) Minor stops (f) Reduced speed losses Proprietary Technology This involves design of production equipment, which provides for (a) Extent of Automation (b) Maintenance free operation (c) Easy start up (d) Life cycle costing (e) Energy usage

(g) Quality Maintenance

Objectives

• To build quality through equipment,

• To ensure that no product defects are caused by faulty equipment, and

 • To build a reliable production line (zero failures). Methodology To achieve these objectives TPM uses, MTBF and MQM (Man-Quality-Machine) management and also dissects operating mistakes to determine, if additional training or use of fail-safe devices. Work Place Organisation and 5S Frame Work TPM organisation of work place along five dimensions is known as 5S (in Japanese) frame work (a) Organisation (b) Orderliness (c) Attention to details (d) Cleanliness (e) Discipline The focal idea of 5S work place organisation is identifying all the subtle abnormalities that might cause failures or defects if not discovered and treated.

The purpose of TPM licensing system is to expand an operator’s capabilities by developing new skills and promoting operational stability. The system also encourages acquisition of skills necessary to perform multiple jobs, creating a multi functional work force. The usual management of Plan-Do-Check-Act cycle of work place organization

Qualitative management through P-D-C-A

(a) Licensing program (b) Procedures and Standards (c) Training (d) Layouts organised by type and function (e) Inspection Plan (f) Re-layouts (g) Inspections and Hourly checks (h) Evaluation (i) Major clean up and Cleaning work tools.

 (h) Planned Maintenance

Objectives

• To maximise performance of the equipment.

 • To minimise cost in maintenance.

 • To achieve zero equipment breakdown.

 Methodology

• Establish predictive maintenance system.

• Establish corrective maintenance system.

 • Establish preventive maintenance system.

 • Establish training system for maintenance crew and supervisors.

• Detailed activity planning for planned maintenance.

Companies that plan to implement TPM should aim for Zero breakdowns and Zero defects. Every company that adopts TPM approach must adopt three imperatives.

(a) The quality and functioning of equipment must change.

(b) The equipment operators must change their way of thinking about equipment.

(c) As a result, work place itself must change drastically. TPM will not be successful in companies that will not make change in cultures – decision making responsibility must be pushed to lower levels of hierarchy.

Predictive Maintenance The aim of predictive maintenance is early prediction of failures by judicious application of condition monitoring techniques and instrumentation. The objective of such a philosophy is to predict failures in advance, so that maintenance actions can be planned to take place at a time convenient to man and machine, and unplanned interruption of production system are minimized. But this needs high technological competence, versatile knowledge of the equipment and effective information system.

Total Quality Management (TQM) Total quality and total productivity are strategic management concepts combining quality and productivity. Total quality aim of delivering highest quality at lowest price is unachievable unless total productivity unachieved. The quality of work at each step is dependent upon man, methods, machines, materials and environment which management creates.

 TQM has four segments :

 (a) Total Quality Control (TQC)

 (b) Total Waste Control (TWC)

(c) Total Employee Involvement (TEI)

(d) Continuous Improvement (KAIZEN)

TPM and TQC

 Both TPM and TQC are aimed at corporate improvement. However there are slight differences.

 (a) The subject of management is quality in TQC and equipment in case of TPM.

(b) TQC aims in management that implements systematisation and standardisation. TPM aims in realisation of proper form of equipment and work place.

(c) TQC imparts personnel training in QC Techniques while TPM imparts training in maintenance engineering and maintenance skills.

(d) TQC aims in voluntary QC aids but in TPM small group activities are integral part in how work place is organised.

 (e) The goal of TQC is quality while TPM aims in elimination of loss and waste.

 (f) TQC aims in process inspection and proof mechanisms TPM aims in condition based maintenance and preventive maintenance and maintenance prevention.

 (g) TQC makes use of statistical process control/control charts TPM makes use of machine failure records/MTBF.

ZERO BREAKDOWN

Physical condition of equipment deteriorates due to many reasons, one of them is usage. The deterioration could be external (visible) or internal (invisible). If the deterioration or decay or defects are not noticed in right time, the equipment breaks down. Therefore, the plant engineer is required to go on keen observation of the equipment conditions regularly so as to forestall the occurrence of any breakdown. To achieve zero breakdown (i.e. no breakdown) the important steps are listed below :

 (a) Rectify design deficiency (as soon as it is identified).

 (b) Rectify the deterioration so as to bring the condition nearest to its original state.

 (c) Stick to optimum operating conditions (as prescribed by OEM in the manual).

 (d) Maintain the basic equipment conditions (by proper and timely cleaning, lubricating, bolt tightening, etc.). (e) Improve maintaining and operating skills.

The production personnel have to perform the following functions :

 (a) Basic maintenance functions such as cleaning, checking of lubricant, water, grease, tightness of nut, screw, etc.

(b) Detect deterioration in functional performances through wear debris size and/or size distribution, product quality, noise level, smoke level, temperature of cooling water, consumption of lubricating oil, grease, etc.

(c) Maintain operating conditions as specified in equipment manual given by OEM or as suggested by maintenance department. (d) Enhance technical skill for set-up, operation, adjustments and visual inspection.

Zero Defects (ZD) and Zero Break Downs (ZBD)

. The goal of zero defects is to create a means of promoting perception on essential elements in the pursuit of quality.

 (a) The definition of quality is confirmation to requirements.

 (b) The system of defect prevention.

(c) The performance standard is zero defects.

(d) The measurement of quality is the price of non-conformance. Zero defects and productive maintenance have a common philosophy.

While zero defects strive to prevent defects, productive maintenance has emphasized the importance of preventing breakdowns. Since equipment failure is a type of defect, both ZD and PM, in effect are preventive systems aimed in eliminating defects. In TPM operators themselves are the inspectors responsible for quality assurance. ZD is considered a significant factor in the success of just in time production system as well.

Five Counter Measures for Zero Break Down Ideally, breakdowns can be eliminated by maintenance prevention (MP) or adoption of maintenance free design. Defects that go undetected and untreated are called hidden defects. To eliminate failures, we must expose hidden defects and treat equipment before it breaks down. The following five steps help eliminate failures :

 (a) Maintaining well regulated basic conditions (cleaning, lubricating and bolting).

 (b) Adhering to proper operating procedures.

(c) Restoring deterioration.

(d) Improving weaken in design.

 (e) Improving operation and maintenance skills.

EXPECTED CONTRIBUTION BY APPLICATIONS OF TPM Increase in

 (a) Labour productivity.

 (b) Small-group activities.

(c) Confidence and morale of operators, maintenance personnel.

(d) Innovative ideas generation.

(e) Reliability in meeting supply schedule.

(f) Functional and physical life of the equipment.

(g) Output of the equipment and machinery.

(h) Value addition to the operators and maintenance crew.

(i) Amicable relationship between production and maintenance group.

Reduction in

 (a) Breakdowns.

 (b) Energy wastage.

 (c) Wastage and re-work.

 (d) Stock of raw-material and semi-finished components stock.

 (e) Accidents.

(f) Customer complaints.

 (g) Maintenance cost.