TPM (Total Productive Maintenance) emerged in Japan thanks to the efforts of the Japan Institute of Plant Maintenance (JIPM) as a system destined for achieving the elimination of so-called ‘six great losses’ of equipment, in order to facilitate the implementation the way of working “Just in time”.By Santiago García Garrido
The philosophy of TPM
TPM is a maintenance philosophy aimed at eliminating production losses due to equipment status, or in other words, keeping equipment in a position to produce at maximum capacity, the expected quality products, with no unscheduled stops. This includes:
- Zero breakdowns
- Zero downtime
- Zero failures attributed to poor condition of equipment
- No loss of efficiency or production capacity due to this equipment
It is understood perfectly the name: total productive maintenance, or maintenance that provides maximum or total productivity.
The eternal fight between maintenance and production
Maintenance has traditionally been seen with a separate and external part to the production process. TPM emerged as a need to integrate the maintenance department into the operation or production one to improve productivity and availability. In a company that TPM has been implemented, all the organization works on maintaining and improving equipment. It is based on five principles:
- All staff participation, from senior management to plant operators. Including every one of them can guarantee the success of the objective.
- Corporate culture creation oriented to obtain maximum efficiency in the production system and management of equipment and machinery. ‘Global efficiency’ is pursued.
- Management system implementation of production plants to facilitate the elimination of losses before they happen.
- Preventive maintenance implementation as an essential mean to achieve the objective of zero losses through integrating activities in small groups and it is based on the support provided by the autonomous maintenance.
- Management systems implementation of for all aspects of production, including design and development, sales and management.
Six great losses
Since the philosophy of TPM, it is considered that a machine stop for making a change; a breakdown in a machine; machine which does not work at 100% of capacity or that manufactures defective products; are intolerable situations which cause losses to the company. The machine should be considered unproductive in all these cases, and appropriate actions designed to avoid them in the future should be taken. TPM identifies six sources of loss (called the ‘six great losses’) that reduce the effectiveness because of interfering with the production:
- Equipment failure, producing unexpected loss of time.
- Commissioning and machine settings (or downtime), which produce loss of time to start a new operation or another stage of it. For example, in the early morning, when changing workplace, when changing a mould, or when making an adjustment.
- Idle, waits and minor stoppages (minor failures) during normal operation which cause loss of time, either by problems in the instrumentation, small obstructions, etc..
- Reduction of operation speed (the machine does not operate at full capacity), which causes production losses because the design speed of the process is not achieved.
- Defects in the process, production losses happen because we need to remake parts of it, reprocess defective products or complete unfinished activities.
- Loss of time typical from commissioning of a new process, idle, probationary period, etc…
Careful analysis of each of these causes of low productivity leads to finding solutions to eliminate them and the means to implement these last ones. It is essential that the analysis is done by the production staff and maintenance staff together, because the problems that cause low productivity are from both types and solutions should be adopted in an integral way to their success.
Participation of the operator in maintenance tasks
From a practical point of view, implementing TPM in an organization means that maintenance is perfectly integrated into production. Therefore, part of the maintenance work have been transferred to production staff, who no longer feels the equipment like something that others take care of it, but as their own, they have to pamper and repair it, the operator feels the equipment as his.
Maintenance involves differences in three levels:
- Operator’s level, who will be responsible for operative maintenance tasks that are very simple, such as cleaning, adjustment, parameters monitoring and minor failures repairing.
- Integrated technical level. Within the production team, there is at least one maintenance person who works with the production staff; he/she is just one of them. This person solves problems more significance, for which more knowledge is needed. But he is there, close, so you do not have to tell anyone or wait. The spare part is also decentralized: each production line, even each machine, have everything it takes closely.
- For higher-level interventions, and scheduled overhauls that involve complex dis-assemblies, delicate adjustments, etc., the company has a maintenance department which is not integrated into the structure of production. But it handles common tools.
Operator’s involvement in maintenance tasks makes him better understand the machine and the installation he is operating, its characteristics and capabilities, its criticality. Also, it helps to work as a team, and it facilitates sharing of experiences and mutual learning, and this improves personal motivation.
There is a fundamental difference between philosophy of TPM and RCM: while the TPC is based on the people and the organization as the center of the process, the RCM maintenance is based on failure analysis, and preventive measures to be taken to avoid them, rather than on people.
TPM implementation in a company
The Japan Institute of Plant Maintenance (JIPM) developed a seven-step method aimed at achieving a change in attitude, which is essential to the success of the program. The steps to develop this change of attitude are:
Phase 1. Initial Cleaning
In this phase, It is tried to clean the machine from dust and dirt, to leave all parts clearly visible. It is also implemented a lubrication program the machine components are fitted and an equipment commission is performed (all known failures are repaired)
Phase 2. Measures to discover the causes of dirt, dust and faults
After cleaning the machine it must not get dirty again and fall into the same state. Causes of dirt, dust and irregular operation must be avoided (oil leaks, for example), access to clean and lubricate difficult places must be improved and to reduce the time needed for these two basic functions (clean and lubricate) is sought.
Phase 3. Preparation of procedures for cleaning and lubrication
In this phase appear again two primary maintenance functions or first level functions, assigned to the production staff: at this stage are prepared standard procedures in order that the activities of cleaning, lubrication and minor adjustments of the components can be done in short time.
Phase 4. General inspections
Once you get that staff be responsible for cleaning, lubrication and minor adjustments, you should train the production personnel so that they can inspect and check the equipment for minor failures and failures in gestation process, and of course, solve them.
Phase 5. Autonomous inspections
In this fifth phase, the ranges of autonomous maintenance or operation maintenance are prepared. In this phase checklists of the machines are prepared by the operators themselves, and then they are put into practice. This is the stage where there is real implementation of periodic preventive maintenance performed by the personnel operating the machine.
Phase 6. Order and Harmony in the distribution
Activities standardization and procedurisation is one of the essences of Total Quality Management (TQM), which is the philosophy behind both the TPM and the JIT. This establishes procedures and standards for cleaning, inspection, lubrication, maintenance of records which reflect all maintenance and production activities, management of tools and spare parts, etc.
Phase 7. Optimization and autonomy in the activity
The last phase aims to develop a culture of continuous improvement across the company: It registers systematically the time between failures, analyzes them and proposes solutions. All this is promoted and led by the production team.
The time required to complete the program varies from 2 to 3 years, and usually is developed as follows:
Management announces to all the company the decision to implement TPM. The program’s success depends on the emphasis put by the General Manager in his announcement to all staff.
It makes a massive campaign of information and training to all levels of the company so that everyone understands clearly the concepts of TPM. All possible means are used, such as lectures, posters, bulletin boards, etc.., So a favorable atmosphere is created to start the program.
Organizations to promote TPM are set up, such as a Management Committee, Departmental Committees and Task Groups to discuss each topic.
Basic policies and goals that will state in the TPM program are defined and issued. To this objective a survey is conducted for all company operations to measure the real effectiveness of the operation team and know the situation with regard to the “6 great losses”. In conclusion, goals are set and a program to fulfill them is proposed.
A master plan for TPM development is defined, which results in a program of all activities and stages.
Once the previous preparatory stage is finished, the “official party” comes to the TPM program a starting ceremony attended by the highest authorities of the company and with guests from all areas.
Begins the analysis and improvement of the effectiveness of each of the equipment of the plant. An information system is defined and is established to record and analyze data for reliability and maintainability
The system is defined and autonomous maintenance groups are formed to start their activities immediately after the “official party”. At this time the maintenance department will work to increase considerably due to the requirements generated by the groups from areas of production.
A scheduled maintenance is implemented at the maintenance department.
It is started the training for operators and maintainers to improve their knowledge and skills.
It creates the improvement system of the plant equipment that allows to implement the ideas of change and design modifications to improve reliability and maintainability.
Finally it is consolidated the full implementation of TPM and you get a high level of team effectiveness. With this purpose, incentives to domestic achievements of TPM program should be created in the various departments of the company.
The hiring of external advice in the process of TPM implementation
The hiring an external company to implement TPM, means hiring a specialist consultancy service responsible for implementing in consecutive phases the total productive maintenance. In general, a single advisor is usually enough. Sometimes counseling takes full time, but this is only profitable if the company has many production lines. Typically, counseling and mentoring process can be done at part time, spending more time at first and gradually leaving the on the production staff hands, the leadership of the implementation project.