Maintenance of equipment is a part of life, particularly if a company is running a manufacturing plant. TPM will bring maintenance to the forefront of the business and ensure it is a top concern for management. With TPM, maintenance can be viewed as a profit activity, generating real dollars as the maintenance is conducted, and therefore is always allowed to squeeze in some maintenance related down time in the manufacturing day. Before TPM, maintenance would be conducted whenever the machine was down because it was broken, or whenever it was down for another reason. Once the TPM program is put into place, the uncontrolled down time due to emergency or unscheduled maintenance is kept to an absolute minimum.
TPM can accomplish many things, but there are five primary reasons a company will switch to the TPM mode of thinking. First, it can reduce cost by reducing the amount of unscheduled downtime associated with a piece of equipment or possibly even an entire production line. Next, quality will either be maintained or increase while the production quantity will increase.
Because the equipment is more reliable, not as much inventory will be kept on hand, leading to lower inventory levels, therefore reducing the costs incurred by a company that has to hold this inventory. Of course, because it is a lean process, it will also avoid the waste associated with pieces of equipment that are not optimized to their highest performance levels. This also costs the company money, time, and sometimes customer satisfaction. Lastly, along the same lines as product quality, the goods that are delivered will be in top shape and send to the customer without defect.
There are four different types of maintenance associated with TPM. The first, breakdown maintenance, is when an equipment fails, the maintenance is purely conducted to bring it back online and in a condition that it will be sustained online indefinitely. These repairs are typically very costly, result in a large amount of downtime, and occur at random, unpredictable times. It is in the best interest of most companies to keep the breakdown maintenance to a minimum.
Preventative maintenance is exactly what it sounds like. It is maintenance that occurs on a periodic basis, whether it be monthly, weekly, or daily, and is designed to maintain a piece of equipment in the best working order possible, and prevent the occurrence of breakdowns. It also extends the lifetime of the equipment dramatically. Unlike breakdown maintenance, it can be scheduled to coincide with production cycles and planned downtime. Two subsets of preventative maintenance are periodic maintenance and predictive maintenance, with both serving very specific functions in the TPM plan.
Corrective maintenance is another form that fits into the TPM puzzle. With corrective maintenance, the equipment is improved to make up for design flaws or inefficiencies that are associated with the manufacturing, supply, or design process. A good example of this would be upgrades for software which patch vulnerabilities discovered after the software is released.
The last form of maintenance is in a different class, and is called maintenance prevention. While the other three forms are actively fixing problems that have already occurred, maintenance prevention is fixing weaknesses that are going to prevent defects, safety, and failure prevention. It is the act of proactively changing the design at the manufacturing plant such that these changes will effectively improve the product.
Figure (1) demonstrates how other quality tools are intertwined within and work in conjunction with TPM. While TPM can be seen as a higher level concept that incorporates all of these tools, the reality is that these tools support the TPM idea and without them, TPM would be nothing more than time wasted. Take note that 5S is considered the strong foundation that a solid TPM program is built upon. Without the clarity that 5S brings to the workplace, TPM is just another case of trying to find your way in the dark.
TPM is a very high level program that must begin at the CEO level. Because it effects all stages of the lifecycle and involves implementing large programs with very deep cuts into resources, as well as significant design, supply, and quality changes, it should be approved at no less than the highest level of management. Usually the best TPM programs have some method of feedback, however, in which the workers who will be performing the maintenance have the opportunity to voice their opinion and offer suggestions.
As stated before, TPM has the capacity to reduce downtime, improve product quality, improve reliability, and make life for employees inside a company much more enjoyable. It is ,however, a very large program to implement, and in doing so many incur significant upfront costs that don’t always have immediate recognizable returns on investments. In the long run, however, TPM should be integrated into every company’s equipment life cycle plan.