What is Total Productive Maintenance (TPM)?
Total Productive Maintenance (TPM) is a comprehensive approach to maintenance management and equipment reliability that originated in Japan. It aims to optimize the productivity and efficiency of manufacturing processes while minimizing downtime, defects, and waste. TPM focuses on involving all levels of an organization, from operators to top management, to collaboratively improve equipment effectiveness and overall operational performance.
Table of Content
- 1 What is Total Productive Maintenance (TPM)?
- 2 Objectives of TPM
- 3 Predictive Maintenance
- 4 Objectives of Predictive Maintenance in TQM
- 5 Optimal Maintenance Costs
- 6 Total Preventive Maintenance
- 7 Overall Equipment Efficiency (OEE)
- 8 Pillars of TPM
- 9 Terotechnology
- 10 Steps in Tpm Implementation
- 10.1 Announcing the Top Management Decision’s to Implement TPM
- 10.2 Educating about TPM
- 10.3 Promoting the TPM Programme
- 10.4 Defining the Basic TPM Policy and Goals
- 10.5 Preparing a TPM Master Plan
- 10.6 Starting TPM Initiatives
- 10.7 Creating a Corporate Constitution
- 10.8 Creating an Early Management System
- 10.9 Developing a Quality Maintenance System
- 10.10 Building an Effective Administration and Support System
- 10.11 Developing a Health, Safety and Environment Management System
- 10.12 Sustaining Complete Tpm Implementation and Raising Levels
Manufacturing organisations need to keep their machines in a good condition in order to ensure a smooth flow of production. If it is not done so, it affects the production process adversely. This leads to the manufacturing of poor quality products or delayed production and the late delivery of products to customers, which can affect the organisation’s image in the market. Further, this results in competitors taking an advantage of the situation. Thus, a Total Productive Maintenance (TPM) is needed by organisations to ensure that all their machines are in a good working condition to enhance productivity levels.
Total Productive Maintenance (TPM) is a system wherein the reliability of machines and equipment is improved and sustained through various activities such as systematic inspection, detection and prevention of incipient failures before they turn into major failures, etc.
Through TPM, one tries to diagnose a machine’s condition and assists in providing necessary solutions to ensure that equipment can be reused. Thus, TPM is also referred to as the ‘medical science’ of machines. The Japan Institute of Plant Maintenance (JIPM) defined TPM as a maintenance system that encompasses all divisions of equipment’s life, including planning, manufacturing and maintenance.
TPM requires the participation of complete workforce from top management to plant personnel. It aims at making optimal utilisation of plant capability with:
- Reduction in equipment failures
- Enhancement in equipment capability (quantitatively and qualitatively)
- Effectiveness of health and safety practices
Objectives of TPM
TPM is mainly adopted by manufacturing organisations to eliminate waste and redundant activities that incur high costs and may even cause delays in production.
Apart from that, some other important objectives of TPM are to:
- Establish a collective culture wherein everybody participates for the attainment of maximum efficiency in all production processes
- Prevent losses that an organisation may have to bear in the case of sudden breakdowns
- Attain the goals of zero accidents, zero defects and zero breakdowns in manufacturing processes
- Seek involvement of both top management as well as production workers in TPM programmes
- Integrate production teams’ activities with other functional teams’ activities to obtain zero production losses
- Produce quality goods
- Eliminate the following six big losses that may occur due to waste and redundant activities:
- Long and expensive repairs caused due to breakdown
- Long-time taken for setups and changeovers
- Reduction in the speed of equipment functioning causing an increase in production cycle time
- Losses that may be caused due to idling and minor stoppage of equipment
- Rework and defects that may cause loss of quality and dissatisfaction to customers
- Losses that may occur due to the loading of new products in a production line till the production gets stabilised
- Long and expensive repairs caused due to breakdown
Predictive maintenance is adopted by organisations to ascertain a machine or equipment’s condition to predict and schedule its maintenance. It mainly helps an organisation to predict machine/equipment failure and take required measures beforehand. This is done by using various tools and techniques to identify loopholes in machines. The key to performing successful maintenance is to get ‘the right information at the right time’ so that the maintenance needs of equipment can be ascertained on time.
Predictive maintenance mainly requires monitoring the performance of a machine/equipment regularly to identify problems and take necessary measures for its repair.
Techniques of Predictive Maintenance
It is a technique wherein infrared cameras are used to get thermal images of machines and equipment to identify any hotspots. These hotspots are generated by heat, wear and tear and malfunctioning electrical circuits as they get displayed on thermal images. By identifying hotspots, one can pinpoint problems much before their occurrence.
It is a predicative maintenance technique wherein the vibrations of a machine are monitored with the help of either handheld vibration analysers or automated monitors. When a part of a machine begins to wear or fail, different vibrations are generated. The analysis of vibrations can help in identifying problems and comparing the readings against known failure modes; thereby pointing out the exact location of problems.
It is conducted to identify leaks of oil and other fluids, such as coolants to detect the wear and tear of machines. In other words, it is a routine activity of examining the properties of lubricants and suspended contaminants in order to obtain accurate information on a machine’s working condition.
By conducting emission tests of waste gases, one can easily know the state of machinery and detect problems at the start before they turn into failures. In addition, the test also helps an organisation to employ proper checks and implement processes to keep the effect of harmful emissions on the environment in control.
It involves monitoring a machine’s performance through sensors that measure vibration, temperature and other parameters to identify any significant changes that may be indicative of fault. Condition monitoring can be done by adopting various methods, such as vibration analysis and oil analysis.
Objectives of Predictive Maintenance in TQM
The main objective of predictive maintenance is to forecast future errors and defects in machines and equipment, thereby preventing delays and building quality in production.
Some other important objectives of adopting predictive maintenance in TQM are to:
- Facilitate plant optimisation by establishing best procedures and practices for critical production systems in a manufacturing plant
- Improve reliability of equipment by predicting defects beforehand and planning the schedules for maintenance
- Eliminate the need for major rebuilds and related downtime
- Reduce the costs of maintenance
- Maintain the functionalities of machines and equipment for a long time
Optimal Maintenance Costs
Optimal maintenance refers to a discipline in production and operations management that involves maintaining a system in a way that maximises profit and minimises cost. Cost parameters are based on the reliability, availability and maintainability features of the concerned system. Some of these parameters are the cost of failure, cost per time unit of downtime (for instance, revenue costs), cost per time unit of corrective maintenance, cost per time unit of preventive maintenance and cost of repairable system replacement.
Optimal maintenance helps to keep equipment in a good condition; however, it incurs costs. For instance, the maintenance strategy of a manufacturing organisation would have both preventive and corrective maintenance costs.
Therefore, the maintenance strategy of a manufacturing organisation needs to be optimised for minimum maintenance costs in an accepted reliability situation. Organisations can keep high maintenance costs down by using a Particle Swarm Optimisation (PSO) algorithm. The results from the use of this algorithm have depicted that optimal maintenance can enhance the reliability of equipment while keeping the cost of maintenance to satisfactory levels.
Total Preventive Maintenance
Total preventive maintenance is a method of planning tasks to be carried out for maintaining machines in working conditions. The main aim behind implementing a total preventive maintenance programme is to eliminate failures in the beginning of the manufacturing process, extend the operational life of machines and minimise the impact of wear and tear.
Further, it can help organisations in implementing an effective routine preventive programme that helps operators in making speedy decisions related to machines’ operations. This would further help in reducing disruptions at the occurrence of unpredictable failures.
Four Types of Preventive Maintenance
It involves performing maintenance activities as and when any problem occurs in a machine. It applies various technologies, such as electronics and sensor technology to ascertain if the limits of pre-defined standards have been exceeded to take appropriate actions. For example, monitoring the condition of a lubricant in a machine.
Time-based Preventive Maintenance
It is performed at regular time intervals; for instance, weekly, monthly, quarterly and annually. For this, schedules are prepared based on the duration of the presence of machines in a plant irrespective of their usage. For example, a water purifying system requires maintenance bi-annually regardless of the time period it has been utilised.
Work-based Preventive Maintenance
It is performed after the fixed hours of usage. For example, checking of boiler level alarms after every 24 hours. Work-based maintenance is often difficult to supervise; thus needs to be tracked automatically.
Opportunity-based Preventive Maintenance
It relies on the availability of machines. In other words, maintenance can only be performed in the event of the non-use of machines. However, the main disadvantage of total preventive maintenance is that it requires planning, time and resources which may cause delays in production.
Overall Equipment Efficiency (OEE)
Overall Equipment Efficiency (OEE) can be described as a set of metrics that emphasises critical success factors for manufacturing organisations. The formula for calculating OEE is:
OEE = Availability × Performance Rate × Quality Rate
Thus, for calculating OEE, three factors have to be determined, which are as follows:
- Availability: It represents the percentage of planned time for which equipment is available to function. Such time is also referred to as uptime. It ensures that the number of breakdowns and downtime do not exceed the planned downtime. Availability is calculated as:
Required availability is the total time equipment needs to operate minus miscellaneous downtime caused due to breaks, schedule lapses and meetings. Downtime includes the actual time the equipment is down for repairs. The goal for organisations is to achieve more than 90 per cent.
- Performance rate: It measures how effectively a process is carried out against pre-defined targets and represents speed losses that may occur during the production process. It is calculated as:
Design cycle time is taken as a unit of production. Output includes the total production for a given time period. Operating time is the availability obtained. The goal for organisations is to achieve more than 95 per cent
- Quality rate: It considers quality loss, i.e. the products which have not been produced as per quality standards. It is calculated as:
Production input is the product unit that is inserted into the process or production cycle. Quality defects are the quantity of products falling below quality standards. The ideal quality rate for organisations is 99.5 per cent.
Combining the ideal percentage of all the three factors, we get:
OEE = 90 per cent × 95 per cent × 99.5 per cent = 85.1 per cent
Thus, the ideal OEE for organisations to achieve is 85.1 per cent.
Pillars of TPM
The traditional model of TPM was developed in the 1960s with an aim to improve the efficiency of machines and processes. The model has five pillars, also called the principles of TPM, as its foundation. These pillars are defined to establish the reliability of machines and processes.
Let us discuss these pillars in detail:
Jishu Hozen (Autonomous Maintenance)
In this type of maintenance, basic maintenance activities such as cleaning, lubricating, oiling, tightening of nuts and bolts and inspection are carried out by machines on the shop floor itself.
Thus, maintenance staff can focus on complex issues that require technical skills and knowledge. The main benefits of autonomous maintenance are:
- Enhancement of skills of workers as they become aware of the functioning of equipment
- Optimal utilisation of machines as their basic maintenance is carried out more often
- Identification and correction of problems before they lead to major breakdowns
- Reduction in overall system downtime as engineers can devote their time to perform high-level maintenance activities
It involves developing cross-functional teams to work on dysfunctional machine/equipment and suggesting appropriate measures. These teams comprise a large number of employees from all functions, thereby bringing vast experience to solve problems quickly.
After the team is formed, the members map the current state of affairs to compare the future performance after improvement. In addition, these teams also ensure that their solutions are implemented and follow-up activities are carried out as decided in the agreed timelines. Thus, this pillar of TPM helps an organisation to create a large base of employees that are familiar with the right problem-solving tools.
It involves developing scheduled plans for performing maintenance activities based on the functioning of machines (failure rates and breakdowns). This helps in breaking down the cycle of failures and adding life to machines. Moreover, as maintenance time is scheduled keeping in mind production deadlines, rare disruptions occur in the manufacturing process. Thus, planned maintenance:
- Brings reduction in breakdowns by constantly scheduling the maintenance of machines
- Decreases production disruptions as scheduling is done while taking machines’ availability in consideration
- Reduces capital investment in machinery by increasing the utility of machines
It involves maintaining quality by ensuring that errors are detected and prevented before their occurrence. Quality maintenance helps an organisation to minimise/eliminate defects and reduce costs incurred on rework. Further, improvement activities brought in an organisation address quality issues while implementing permanent counter measures to deal with problems in a machine/equipment.
It deals with bridging a gap created due to a lack of proper knowledge about maintenance in an organisation. This can bring disruptions in the implementation of the TPM programme and can have disastrous results for an organisation. This pillar can, thus, be defined as an organisation-wide initiative involving employees at all levels of an organisation to get acquainted with TPM training. The lower level employees can be taught to perform basic maintenance activities, whereas technical workers can learn about preventive maintenance that requires higher skills. Similarly, top-level managers can learn TPM skills to mentor those who are working under them.
This pillar of TPM can also be implemented in office and administrative functions and support in the adequate functioning of an organisation. This can help organisations in performing value creation processes efficiently.
Safety, Health and Environment
This pillar of TPM lays emphasis on creating the safe environment for workers with no health risks. It also ensures that all the employees are provided a safe environment to work and any risk or harmful conditions that may be detrimental to the health of employees must be eliminated. Safe environment motivates employees to work efficiently and change their attitude towards their workplace and encourage them to work towards the attainment of goals.
There are 5S that form the base of TPM. Let us now discuss them in detail as follows:
- Sorting: It involves arranging resources at the workplace and eliminating anything that is redundant and waste
- Setting: It involves establishing all the processes to get access to raw materials and other resources easily. Consequently, the waiting and searching time in the process gets significantly reduced; thereby improving the flow of value throughout the value chain.
- Shining (Cleaning): It involves maintaining high standards of quality in the process of production.
- Standardising: It ensures the recording of improvements in documented form to serve as a basis for further improvement and training.
- Sustaining: It involves making improvement through scheduled audits. These audits help in measuring the effectiveness of the established standards.
Terotechnology is an integrated approach adopted by organisations to reduce their life cycle costs, increase the operating life of plant and machinery and ensure all time availability of machine/equipment for use.
The main activities involved in terotechnology are as follows:
- Making decisions related to design, manufacturing and cost targets
- Deciding upon the arrangement of physical resources, plant and equipment
- Determining plant and equipment requirements from different point of views, such as production capability, control of environment, reliability, feasibility and so on
- Establishing the specifications of the equipment and its procurement (whether to be outsourced or built inside)
- Using the plant and equipment after conducting successful tests and inspections
Terotechnology is adopted by many organisations across the world widely and is rapidly gaining importance in various maintenance programmes. The main benefits of adopting terotechnology are as follow:
- Improved maintenance and reliability of plant and equipment
- Reduced costs of maintenance and repairs
- High control on spare part management
- Minimum breakdowns and smooth and uninterrupted production
- Improved efficiencies of operations and better quality of work and life
Steps in Tpm Implementation
TPM implementation is a systematic process that involves a step-bystep approach. There are four phases of TPM implementation: preparation phase, introduction phase, implementation phase and consolidation phase. These phases are further divided into 12 steps. The first five steps come under the preparation phase, while the sixth step comes under the introduction phase. Step 7 to step 11 are covered under implementation phase and step 12 is a part of the consolidation phase.
Announcing the Top Management Decision’s to Implement TPM
In this step, the top management formally announces its intention to implement a TPM programme in the organisation. Moreover, the top management must remain committed to the TPM programme to the end. This increases employees’ commitment and they also view TPM as a long-term initiative and extend their complete support to solve problems that may arise during the implementation of TPM.
Educating about TPM
Before beginning the implementation of the TPM programme, employees must be made familiar with activities involved in the programme. For this, seminars, inhouse training programmes, etc. are conducted for employees.
Promoting the TPM Programme
In this step, a special office is formed that is responsible for promoting TPM. The office comprises permanent staff and various committees and sub-committees that are assigned the work of creating and implementing effective TPM promotion strategies. In addition, the office develops a master plan of TPM promotion, coordinate its activities, design methods to control TPM activities, develop promotional campaigns and distribute the required information.
Defining the Basic TPM Policy and Goals
In this step, a TPM policy needs to be formulated. The policy should be an integral part of the corporate business policy and clearly indicate the goals and direction of the activities to be performed. These goals should reflect an organisation’s long-term and short-term goals. Therefore, all members of the organisation should be consulted while establishing TPM goals. Figure 5.5 shows the example of TPM policy and goals:
Preparing a TPM Master Plan
In this step, a master plan must be developed consisting of activities to be performed for the achievement of TPM goals. The main activities that are generally performed in TPM are autonomous maintenance, focused improvement, planned maintenance, equipment management, predictive maintenance, etc. The master plan must also include the budget and schedule for performing TPM activities.
Starting TPM Initiatives
In this step, the implementation of TPM programme is initiated. The TPM start-off must be designed to increase the morale and motivation of employees. For instance, an organisation can conduct annual meetings to discuss TPM plans accomplished during the period. In this way, the management can show its commitment towards TPM implementation.
Creating a Corporate Constitution
In this step, an organisation must choose and implement activities that would be instrumental in the achievement of TPM goals. These activities are not the same for all organisations and vary depending on the TPM goals of an organisation.
Creating an Early Management System
It involves both early product management and equipment management so that an organisation can obtain products and equipment quickly and cost effectively. The main emphasis of this step remains on addressing different areas of equipment management, such as investment planning, process designing, equipment designing, test operation, etc.
Developing a Quality Maintenance System
In this step, the quality maintenance system is developed that helps in building quality through processes and equipment. Quality maintenance involves the controlling of variability by supervising equipment components affecting it. It must focus on clarifying relationships among major production inputs such as equipment, materials and people and production methods. By applying quality maintenance in the equipment and process design, quality can be built effectively at the early stages of production.
Building an Effective Administration and Support System
In this step, TPM is implemented in administrative and support departments as they have an essential role in the performance of production activities. By adopting TPM in the administrative department, one must aim to build an ‘information factory’ and streamline the information flow. For instance, by implementing autonomous maintenance in the administrative department, the efficiency of administrative functions can be improved.
Developing a Health, Safety and Environment Management System
In this step, the provision of safety must be incorporated in TPM activities. For instance, designing of fail-safe equipment for employees needs to be carried out. Similarly, safety during shut down maintenance should be assured.
Sustaining Complete Tpm Implementation and Raising Levels
Once TPM initiatives are implemented successfully, the organisation needs to embed TPM in its culture and work to make further improvement. An organisation can also incorporate TPM in its vision to keep its long-term orientation.