How does TPM relate to Lean Manufacturing? Total Productive Maintenance (TPM) is really about applying Lean Manufacturing to the way we care for our equipment. TPM is an important part of our Lean Manufacturing initiative, because without it we will experience difficulty as we improve the flow of materials through the introduction of pull systems and the elimination of waste between the steps in our process.
Fundamentally, TPM is about applying flow, takt, standard work and pull systems to the way we maintain and care for our equipment. It is a culture change in the way people care for equipment that is much more than marking, labeling, cleaning machines, or operators doing maintenance work. Total Productive Maintenance is an equipment and process improvement strategy that links many of the elements of a good maintenance program to achieve higher levels of equipment effectiveness. It includes a set of techniques pioneered by Denso in the Toyota Group in Japan, to ensure that each machine in our production process is always able to perform its required tasks.
The approach is called “total” in 4 main areas:
Total Participation supported by “Total” Leadership. Firstly TPM requires the total participation of all employees, not only maintenance personnel but line managers, manufacturing engineers, quality experts and operators. This involves everyone knowing their exact roles and responsibilities, and then executing those roles reliably, on a daily basis. For operators this will involve well developed checklists and simple maintenance tasks set out every shift. We will need to ensure that abnormalities are recorded and reported promptly to maintenance personnel for repair. The maintenance technicians will be required to look for ways to eliminate those problems and at least establish PM’s to ensure the problem does not reoccur. Engineering will be required to aid maintenance in ongoing equipment improvement. And managers will provide the discipline in the system by ensuring relevant metrics are collected and channeled into the problem solving process.
Total Productivity. Secondly TPM is aiming for total productivity of equipment by focusing on the six machine losses: breakdowns, changeovers, minor stops, speed losses, scrap and rework. Years of experience and measuring at Toyota has shown that up to 1/3 of all production downtime is caused by simple limit or proximity switch confirmation failures. Our aim should be to eliminate all production “downtime” and at least as a stopgap aim for “single minute maintenance”- less than 10 minutes for any breakdown.
Total Lifecycle. Thirdly TPM addresses reliability throughout the total life cycle of the equipment to revise maintenance practices, preventative maintenance intervals, activities and improvements depending on where the equipment is in its life cycle. TPM includes daily maintenance by operators, namely simple checking and lubrication that results in early detection and fixing of problems. This aspect is probably one of the most significant aspects of TPM. This may involve more widespread use of “Condition Monitoring”. Specialists become involved to carry out “machine kaizen” or corrective maintenance. At Toyota this is the result of detailed studies over the whole life of the equipment to see where time, spare parts and dollars have been consumed, all in the search of maintenance prevention.
Total Systems approach. TPM also includes a focus on the whole system with a constant effort to improving all aspects of the equipment lifecycle, pursuit of efficiency and participation by everyone. This includes linking and improving all support activities eg employee training and development, spare parts management, document control, maintenance data collection and analysis, and feedback to equipment vendors.
Unlike traditional reactive and preventative maintenance, which relies on maintenance personnel, TPM involves operators in routine maintenance, improvement projects and simple repairs. This would typically include daily activities such as lubrication, cleaning, tightening and inspecting equipment.
In this way, for those of us with equipment centric processes, TPM is an important part of Lean Manufacturing.
Adapted from Robert M Williamson - Strategic Work Systems and the Lean Lexicon - Lean Enterprise Institute