Conducted on a regular basis, TPM can potentially transform equipment maintenance across industry and there are six key elements behind this proven strategy.

Ask the average plant floor worker what they think about Total Productive Maintenance (TPM), and they might tell you it’s a set of rules that can better be summed up by the concepts of operator-performed maintenance or autonomous maintenance. But TPM is much more than that. This maintenance strategy represents nothing less than a cultural shift in the workplace in the way employees think about and care for equipment. When put into effect, the results of TPM can be profound.

Total Productive Maintenance, an offshoot of the Toyota Production System in Japan in the late 1960s, is a strategy to improve equipment performance that links proven maintenance elements together to achieve a high level of equipment effectiveness. The six key elements of TPM include:

• Improving equipment effectiveness by targeting the major losses

• Involving operators in the daily, routine maintenance of their equipment

• Improving maintenance efficiency and effectiveness

• Training for everyone involved

• Life-cycle equipment management and maintenance prevention design

• Winning with teamwork focused on common goals

The result of these six elements working together to improve equipment performance and reliability is TPM in a nutshell. No one element, removed from its partners, can create the effects achievable by this strategy, nor will any combination missing even one element. The six elements are interrelated and designed to support each other. It is perhaps the lack of this comprehensive approach that has resulted in 50% of TPM initiatives being abandoned since it was introduced to U.S. in 1986.

The logic behind TPM can be grasped more easily by having an understanding of the Toyota Production System, the tradition behind it. But, until recently, a working definition of the Toyota Production System has been hard to pin down. This is because the Toyota Production System is the accumulated result of a trial and error process over the course of five decades and has never been written down. Fortunately, two Harvard researchers, H. Kent Bowen and Steven Spear, spent four years studying this system, and have recently published their findings. In their article “Decoding the DNA of the Toyota Production System,” the authors isolate the four rules that govern the system. They are as follows:

• All work shall be highly specified as to content, sequence, timing, and outcome.

• Every customer-supplier connection must be direct, and there must be an unambiguous yes-no way to send requests and receive responses.

• The pathway for every product and service must be simple and direct.

• Any improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organization.

(From “Decoding the DNA of the Toyota Production System,” Harvard Business Review, September-October 1999, H. Kent Bowen and Steven Spear)

The first three rules illustrate the actual processes of TPM and what roles each person involved in maintenance must play. The fourth rule expands this structure to comment on how to solve problems and improve overall performance. With that in mind, the first rule, “all work shall be highly specified as to content, sequence, timing, and outcome”, dictates that anything done to maintain and improve equipment must be documented in procedures that every employee follows. This documentation should include detailed information on the parts used, labor hours involved, descriptions of the problems that arose, the estimated root causes of the problems and the corrective measures taken to solve the problem. It also means that maintenance work is governed by planned maintenance routines and that frequent joint production/maintenance planning and status meetings are scheduled to keep efforts focused.

The second rule, “every customer-supplier connection must be direct, and there must be an unambiguous yes-no way to send requests and receive responses”, means that proper maintenance tools, parts, and supplies be made available, as they are needed. It also means that spare parts are adequately maintained and that maintenance requests are sent and acknowledged promptly. Visual systems and signals can be used to eliminate long drawn-out explanations and reading. Lastly, when proper repairs or improvements are made, those who requested them should sign off on them.

The third rule, which states that the “pathway for every product and service must be simple and direct” requires every equipment operator to know exactly where to go for help with an equipment problem. By extension, this means that every maintenance person knows on what equipment he is qualified to work and where he or she can get help when a problem exceeds their expertise. Finally, this rule necessitates that the documentation for specific equipment remain accessible to those who need it.

The fourth rule, “any improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organization” indicates that data should be collected, analyzed, and made available to make the improvements more efficient and effective. Additionally, informed people closest to the problem should work out possible solutions and conduct experiments to determine the workability of their solutions. Applying the logic of this rule also requires that formally experienced and trained problem solvers lead improvement effort and that changes are made in the equipment and supporting work processes and people are trained in the new methods.

As one can see, a great amount of discipline is required in the workplace to sustain the application of TPM strategies. Fields as diverse as aircraft assembly, petroleum exploration and even racecar equipment maintenance have successfully put TPM strategies into use, their only commonality being the high degree of discipline that each of these callings demand. The four rules described above define the disciplined approach that Total Productive Maintenance requires to produce the optimum results.

Sources: TPM: An Often Misunderstood Equipment Improvement Strategy
Robert M. Williamson
Maintenance Technology Magazine
http://www.mt-online.com/current/04-00tpm2.html

Decoding the DNA of the Toyota Production System
H. Kent Bowen and Steven Spear
Harvard Business Review, September-October 1999