Total productive maintenance (TPM) is a maintenance program, which involves a newly defined concept for maintaining plants and equipment. The goal of the TPM program is to markedly increase production while, at the same time, increasing employee morale and job satisfaction. It can be considered as the medical science of machines.
TPM brings maintenance into focus as a necessary and vitally important part of the business. It is no longer regarded as a non-profit activity. Downtime for maintenance is scheduled as a part of the manufacturing day and, in some cases, as an integral part of the manufacturing process. The goal is to hold emergency and unscheduled maintenance to a minimum.
TPM was introduced to achieve the following objectives. The important ones are listed below.
- Avoid wastage in a quickly changing economic environment.
- Producing goods without reducing product quality.
- Reduce cost.
- Produce a low batch quantity at the earliest possible time.
- Goods send to the customers must be non-defective.
Similarities and Differences between TQM and TPM
The TPM program closely resembles the popular Total Quality Management (TQM) program. Many of the tools such as, employee empowerment, benchmarking, documentation, etc. used in TQM are used to implement and optimize TPM. Following are the similarities between the two:
- Total commitment to the program by upper level management is required in both programs,
- Employees must be empowered to initiate corrective action, and
- A long-range outlook must be accepted as TPM may take a year or more to implement and is an on-going process. Changes in employee mind-set toward their job responsibilities must take place as well.
The differences between TQM and TPM are summarized below.
Pillars of TPM
TPM starts with 5S. Problems cannot be clearly seen when the work place is unorganized. Cleaning and organizing the workplace helps the team to uncover problems. Making problems visible is the first step of improvement.
This means sorting and organizing the items as critical, important, frequently used items, useless, or items that are not need as of now. Unwanted items can be salvaged. Critical items should be kept for use nearby and items that are not be used in near future, should be stored in some place. For this step, the worth of the item should be decided based on utility and not cost. As a result of this step, the search time is reduced.
The concept here is that “Each item has a place and only one place”. The items should be placed back after usage at the same place. To identify items easily, name plates and colored tags has to be used. Vertical racks can be used for this purpose, and heavy items occupy the bottom position in the racks.
SEISO—Shine the Workplace
This involves cleaning the work place free of burrs, grease, oil, waste, scrap etc. No loosely hanging wires or oil leakage from machines.
Employees has to discuss together and decide on standards for keeping the work place/machines/pathways neat and clean. These standards are implemented for whole organization and are tested/inspected randomly.
Considering 5S as a way of life and bring about self-discipline among the employees of the organization. This includes wearing badges, following work procedures, punctuality, dedication to the organization etc.
PILLAR 2—JISHU HOZEN (AUTONOMOUS MAINTENANCE)
This pillar is geared towards developing operators to be able to take care of small maintenance tasks, thus freeing up the skilled maintenance people to spend time on more value added activity and technical repairs. The operators are responsible for upkeep of their equipment to prevent it from deteriorating.
Steps in JISHU HOZEN
- Train the employees:
Educate the employees about TPM, its advantages, JH advantages and steps in JH. Educate the employees about abnormalities in equipments.
- Initial cleanup of machines
- Supervisor and technician should discuss and set a date for implementing step 1.
- Arrange all items needed for cleaning.
- On the arranged date, employees should clean the equipment completely with the help of maintenance department.
- Dust, stains, oils and grease has to be removed.
- Following are the things that have to be taken care while cleaning. They are oil leakage, loose wires, unfastened nits and bolts and worn out parts.
- After clean up problems are categorized and suitably tagged. White tags are place where operators can solve problems. Pink tag is placed where the aid of maintenance department is needed.
- Contents of tag are transferred to a register.
- Make note of area, which were inaccessible.
- Finally close the open parts of the machine and run the machine.
- Counter measures
- Inaccessible regions had to be reached easily, e.g., if there are many screw to open a flywheel door, hinge door can be used. Instead of opening a door for inspecting the machine, acrylic sheets can be used.
- To prevent work out of machine parts necessary action must be taken.
- Machine parts should be modified to prevent accumulation of dirt and dust.
- Tentative standard
- JH schedule has to be made and followed strictly.
- Schedule should be made regarding cleaning, inspection and lubrication and it also should include details like when, what and how.
- General inspection
- The employees a re trained in disciplines like pneumatics, electrical, hydraulics, lubricant and coolant, drives, bolts, nuts and safety.
- This is necessary to improve the technical skills of employees and to use inspection manuals correctly.
- After acquiring this new knowledge the employees should share this with others.
- By acquiring this new technical knowledge, the operators are now well aware of machine parts.
- Autonomous inspection
- New methods of cleaning and lubricating are used.
- Each employee prepares his own autonomous chart/schedule in consultation with supervisor.
- Parts which have never given any problem or part which don’t need any inspection are removed from list permanently based on experience.
- Including good quality machine parts. This avoids defects due to poor JH.
- Inspection that is made in preventive maintenance is included in JH.
- The frequency of cleanup and inspection is reduced based on experience.
- Up to the previous stem only the machinery/equipment was the concentration. However, in this step the surroundings of machinery are organized. Necessary items should be organized, such that there is no searching and searching time is reduced.
- Work environment is modified such that there is no difficulty in getting any item.
- Everybody should follow the work instructions strictly.
- Necessary spares for equipments is planned and procured.
- Autonomous management
- OEE and OPE and other TPM targets must be achieved by continuous improve through Kaizen.
- PDCA (Plan, Do, Check and Act) cycle must be implemented for Kaizen.
‘Kai’ means change, and ‘Zen’ means good (for the better). Basically Kaizen is for small improvements, but carried out on a continual basis and involve all people in the organization. Kaizen is opposite to big spectacular innovations. Kaizen requires no or little investment. The principle behind is that “a very large number of small improvements are more effective in an organizational environment than a few improvements of large value.” This pillar is aimed at reducing losses in the workplace that affect our efficiencies. By using a detailed and thorough procedure we eliminate losses in a systematic method using various Kaizen tools. These activities are not limited to production areas and can be implemented in administrative areas as well.
- Practice concepts of zero losses in every sphere of activity.
- Relentless pursuit to achieve cost reduction targets in all resources.
- Relentless pursuit to improve overall plant equipment effectiveness.
- Extensive use of PM analysis as a tool for eliminating losses.
- Focus of easy handling of operators.
Achieve and sustain zero loses with respect to minor stops, measurement and adjustments, defects and unavoidable downtimes. It also aims to achieve 30% manufacturing cost reduction.
Tools used in Kaizen
- PM analysis
- Why-Why analysis
- Summary of losses
- Kaizen register
- Kaizen summary sheet.
The objective of TPM is maximization of equipment effectiveness. TPM aims at maximization of machine utilization and not merely machine availability maximization. As one of the pillars of TPM activities, Kaizen pursues efficient equipment, operator and material and energy utilization, which is extremes of productivity and aims at achieving substantial effects. Kaizen activities try to thoroughly eliminate 16 major losses.
16 Major Losses in an Organization
PILLAR 4—PLANNED MAINTENANCE
It is aimed to have trouble free machines and equipments producing defect free products for total customer satisfaction. This breaks maintenance down into 4 ‘families’ or groups, which was defined earlier.
- Preventive maintenance
- Breakdown maintenance
- Corrective maintenance
- Maintenance prevention
With planned maintenance, we evolve our efforts from a reactive to a proactive method and use trained maintenance staff to help train the operators to better maintain their equipment.
- Achieve and sustain availability of machines;
- Optimum maintenance cost;
- Reduces spares inventory; and
- Improve reliability and maintainability of machines.
- Zero equipment failure and breakdown;
- Improve reliability and maintainability by 50%;
- Reduce maintenance cost by 20%; and
- Ensure availability of spares all the time.
Six Steps in Planned Maintenance
- Equipment evaluation and recoding present status;
- Restore deterioration and improve weakness;
- Building up information management system;
- Prepare time based information system, select equipment, parts and members and map out plan;
- Prepare predictive maintenance system by introducing equipment diagnostic techniques; and
- Evaluation of planned maintenance.
PILLAR 5—QUALITY MAINTENANCE
It is aimed towards customer delight through highest quality through defect free manufacturing. Focus is on eliminating non-conformances in a systematic manner, much like Focused Improvement.
We gain understanding of what parts of the equipment affect product quality and begin to eliminate current quality concerns, then move to potential quality concerns. Transition is from reactive to proactive (Quality Control to Quality Assurance).
QM activities is to set equipment conditions that preclude quality defects, based on the basic concept of maintaining perfect equipment to maintain perfect quality of products. The conditions are checked and measure in time series to very that measure values are within standard values to prevent defects. The transition of measured values is watched to predict possibilities of defects occurring and to take counter measures before hand.
- Defect free conditions and control of equipments;
- QM activities to support quality assurance;
- Focus of prevention of defects at source;
- Focus on poka-yoke (fool proof system);
- In-line detection and segregation of defects; and
- Effective implementation of operator quality assurance.
- Achieve and sustain customer complaints at zero;
- Reduce in-process defects by 50%; and
- Reduce cost of quality by 50%.
Quality defects are classified as customer end defects and in house defects. For customer- end data, we have to get data on:
- Customer end line rejection; and
- Field complaints.
In-house, data include data related to products and data related to process.
Data Related to Product
- Product-wise defects;
- Severity of the defect and its contribution—major/minor;
- Location of the defect with reference to the layout;
- Magnitude and frequency of its occurrence at each stage of measurement;
- Occurrence trend in beginning and the end of each production/process/changes (like pattern change, ladle/furnace lining etc.); and
- Occurrence trend with respect to restoration of breakdown/modifications/periodical replacement of quality components.
Data Related to Processes
- The operating condition for individual sub-process related to men, method, material and machine;
- The standard settings/conditions of the sub-process; and
- The actual record of the settings/conditions during the defect occurrence.
It is aimed to have multi-skilled revitalized employees whose morale is high and who has eager to come to work and perform all required functions effectively and independently. Education is given to operators to upgrade their skill. It is not sufficient know only ‘Know-How’ by they should also learn ‘Know-Why’. By experience they gain, ‘Know-How’ to overcome a problem what to be done. This they do without knowing the root cause of the problem and why they are doing so. Hence, it becomes necessary to train them on knowing ‘Know-Why’. The employees should be trained to achieve the four phases of skill. The goal is to create a factory full of experts. The different phase of skills is:
Phase 1: Do not know.
Phase 2: Know the theory but cannot do.
Phase 3: Can do but cannot teach.
Phase 4: Can do and also teach.
- Focus on improvement of knowledge, skills and techniques;
- Creating a training environment for self-learning based on felt needs;
- Training curriculum/tools/assessment etc. conducive to employee revitalization; and
- Training to remove employee fatigue and make work enjoyable.
- Achieve and sustain downtime due to want men at zero on critical machines;
- Achieve and sustain zero losses due to lack of knowledge/skills/techniques; and
- Aim for 100% participation in suggestion scheme.
Steps in Educating and Training Activities
- Setting policies and priorities and checking present status of education and training;
- Establish of training system for operation and maintenance skill upgradation;
- Training the employees for upgrading the operation and maintenance skills;
- Preparation of training calendar;
- Kick-off of the system for training; and
- Evaluation of activities and study of future approach.
PILLAR 7—OFFICE TPM
Office TPM should be started after activating four other pillars of TPM (JH, KK, QM, PM). Office TPM must be followed to improve productivity, efficiency in the administrative functions and identify and eliminate losses. This includes analyzing processes and procedures towards increased office automation. Office TPM addresses twelve major losses. They are:
- Processing loss;
- Cost loss including in areas such as, procurement, accounts, marketing, sales leading to high inventories;
- Communication loss;
- Idle loss;
- Set-up loss;
- Accuracy loss;
- Office equipment breakdown;
- Communication channel breakdown, telephone and fax lines;
- Time spent on retrieval of information;
- Non availability of correct on-line stock status;
- Customer complaints due to logistics; and
- Expenses on emergency dispatches/purchases.
Office TPM and its Benefits
- Involvement of all people in support functions for focusing on better plant performance;
- Better utilized work area;
- Reduce repetitive work;
- Reduced inventory levels in all parts of the supply chain;
- Reduced administrative costs;
- Reduced inventory carrying cost;
- Reduction in number of files;
- Reduction of overhead costs (to include cost of non-production/non-capital equipment);
- Productivity of people in support functions;
- Reduction in breakdown of office equipment;
- Reduction of customer complaints due to logistics;
- Reduction in expenses due to emergency dispatches/purchases;
- Reduced manpower; and
- Clean and pleasant work environment.
PILLAR 8—SAFETY, HEALTH AND ENVIRONMENT
- Zero accident,
- Zero health damage, and
- Zero fires.
In this area focus is on to create a safe workplace and a surrounding area that is not damaged by our process or procedures. This pillar will play an active role in each of the other pillars on a regular basis.
A committee is constituted for this pillar, which comprises representative of officers as well as workers. The committee is headed by senior vice President (Technical). Utmost importance to safety is given in the plant. Manager (safety) is looking after functions related to safety. To create awareness among employees various competitions like safety slogans, quiz, drama, posters, etc. related to safety can be organized at regular intervals.
Today, with competition in industry at an all time high, TPM may be the only thing that stands between success and total failure for some companies. It has been proven to be a program that works. It can be adapted to work not only in industrial plants, but also in construction, building maintenance, transportation, and in a variety of other situations. Employees must be educated and convinced that TPM is not just another ‘program of the month’ and that management is totally committed to the program and the extended time frame necessary for full implementation. If everyone involved in a TPM program does his or her part, an unusually high rate of return compared to resources invested may be expected.