The progressive history of equipment management in Japan is divided into the following five stages:
(1) Stage 1: After-the-fact Maintenance
All that was done before 1950 was after-the-fact maintenance (BM: Breakdown Maintenance).
The idea was to wait until something breaks down before repairing it, and even now, when the damage from the stoppage of production equipment can be ignored, it is still possible to adopt a program of after-the-fact maintenance. It is difficult to plan in advance when repair work occurs unexpectedly. Therefore, it is difficult to allocate and arrange personnel, materials, and equipment. However, from the point of view of productivity to integration, if this efficiency can be ignored, it is possible to adopt the maintenance program after the fact.
Aftermaintenance can also be used when the mean time between failures (MTBF) is not certain, the mean time to repair (MTTR) is short, and it is costly to exchange parts regularly.
(2) Stage 2 Preventive Maintenance
Preventive Maintenance (PM: Prevention Maintenance) was introduced to the U.S. around 1950.
This approach is to maintain equipment before it fails.
Preventive Maintenance is an approach to preventing downtime caused by sudden equipment failure, and is a maintenance method in which parts or a Unit are replaced at economical intervals.
Preventive maintenance intervals are determined by the size or life of the equipment, and can be annual, semi-annual, monthly, or weekly for periodic inspections, repairs, or overhaul.
Preventive maintenance can be uneconomical if it is excessive.
Preventive maintenance programs are set up based on the cost of repairs after the fact, the overall productivity, the achievement of production goals, and the turnover rate.
(3) Stage 3: Productive Maintenance
Productive maintenance (PM: productive maintenance) was considered in the 1960s. This is the most cost-effective way of maintaining equipment to ensure that it is more productive. It is a way of deciding how to maintain equipment by combining the cost (LCC: life cycle cost) of the equipment itself, or the cost of keeping the equipment running, with the loss of deterioration and justification of the equipment throughout its life cycle.
There are the following two ways and ideas:
1, improved maintenance (CM: correct maintenance)
In order to make the maintenance and repair of the equipment easier, and furthermore, in order to make it possible to improve the equipment without the need for repair and maintenance, that is to say, through the improvement of the equipment and improve the equipment's productivity of the equipment for the technical improvement.
2, maintenance prevention (MP: maintenance prevention)
In order to fundamentally reduce the cost of maintenance of equipment, rather than just think about how to maintain the method, it is better to manufacture equipment that does not require maintenance or purchase to take into account the maintenance of this matter. This idea maximizes the smoothness and economy of equipment tuning and maintenance, and is called maintenance prevention.
(4) Stage 4: TPM
From 1970, total productive maintenance (TPM: total productive maintenance) was introduced, which included the activities of small groups of workers organized independently.
Nippon Denso published an article entitled "TPM: Total Productive Maintenance" in 1971. Total Productive Maintenance (TPM)? in 1971.
It was pointed out that production prevention (maintenance) is not only the responsibility of the office staff, but also includes all the staff as the center of all the management, management and operators of the company's total type of a total prevention.
Management is the person responsible for promoting production maintenance, and all workers should participate in the activities with enthusiasm. Even though it may not be mature and perfect, it is a sign that the revolutionary TPM activities have been born.
(5) Stage 5 Predictive maintenance
Predictive maintenance (PM: predictive maintenance) was popularized in the 1980s.
Predictive maintenance is the concept of diagnosing the deterioration or performance condition of equipment, and then carrying out maintenance and repair activities based on the diagnosed condition. Therefore, it is a prerequisite to grasp the deterioration status of equipment as accurately and precisely as possible.
Condition-based maintenance (CBM: condition-based maintenance) is the process of observing the state of deterioration and performing maintenance when it is really necessary.
With the improvement of equipment diagnostics and quantitative control of equipment conditions, there has been a recent shift from time-based maintenance to time-based inspection and repair. The transition from inspection and repair to judgment and countermeasures based on the condition of the equipment is taking place.
Time-based maintenance is called time-based maintenance (TBM: time-based maintenance) or scheduled maintenance.