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Total Productive Maintenance

The history of “Total Productive Maintenance (TPM)” starts from what is currently Denso, a Toyota group company.

When we look at their corporate history, there is an interesting sentence.

“Therefore, we recognized the need to collaborate not only with the maintenance group but also the equipment design & manufacturing and the equipment using department.”


How often do we include “Equipment design & manufacturing group” in TPM activities?

Total Productive Maintenance. It is an essential activity for operations.

They say this activity started in Denso, a Toyota group company. The company was founded in 1949. The start of this company was a rough one. Toyota spun this company off because it was losing money. They produced washing machines and electronic irons to rebuild the company. They even tried electric vehicles. In 1953, Denso formed a technological partnership with Bosch.

Denso’s TPM evolution started in 1961 after the partnership ended. They say the first PM was tried on a transfer line and failed despite adding more maintenance crew. Based on this failure, Denso recognized the need to include the equipment designers & manufacturers, and production who use the equipment. This “Trinity” was the beginning of TPM.

This trinity is what grabs my attention. Unfortunately, although “Total” means the entire company, many activities are still maintenance only. Then, some focus on operators and their autonomous maintenance. From such groups of activities, next jumps to “everyone.” But like many other activities, like Total quality management, “everybody” becomes nobody.

The birthplace of TPM, Denso is a very production technology-oriented company. Since the sixties, they have produced their own pieces of equipment. In the mid-eighties, they claimed that they had about 2600 people working in the design & production of equipment. The total number of employees was about 20000, so about 10% of the company was working in manufacturing equipment.

Another fact is that the first machine they implemented, TPM, was the first line they designed internally. And that gives us a hint on how “TPM” started. After failing to stabilize the machine's performance by adding maintenance, the management likely pulled the designers to join the problem-solving activities to improve maintenance. And the designers didn’t escape or had no way to go since it was a time of lifetime employment in Japan. Also, this was a time when Quality Circles were on the rise. Most likely, the designer, maintenance, and production people formed a circle to improve machine stability. Nothing fancy, or they did not have a vision about how maintenance should be. They made all parties who designed, used, and maintained the equipment work together and made them successful.

TPM is clear that everybody should join the activity. This everybody includes vertically and horizontally. Vertical is from the top to the frontline workers. The horizontal is tricky since every business has different functionalities. Only some companies will have the same engineering capability on production equipment as Denso. I guess most original TPM researchers knew about Denso’s uniqueness but tried to cover such capability vaguely since they didn’t want to scare anyone. Although keeping the same engineering capabilities as Denso to conduct TPM is not required, the importance of design and engineering does not diminish.

Having said that, I do not mean to include the equipment manufacturers. I have tried, and it isn't easy to involve them. We often contact the sales team rather than the designers. And the equipment manufacturing business has different motivations. They want to sell more equipment. Once you get them to improve maintenance, there are cases where you end up buying new equipment.

However, the internal process engineering team should be fully involved. My coach used to say, “Engineering who doesn’t understand maintenance is like a spoiled kid who keeps buying new toys and breaking them.” Don’t spoil an engineer. Besides, learning about how machine breaks is valuable knowledge to have. There are many things we can learn from a broken machine. Besides, which inventors do not have a story about how they repaired something before becoming great engineers?

Today’s TPM has eight pillars. Individual Kaizen 【個別改善】、Autonomous Maintenance 【自主保全】、Planned Maintenance 【計画保全】、Education & Training 【教育訓練】、Initial (Design) Management 【初期管理】、Quality Maintenance 【品質保全】、Administrative & Indirect Department Activities 【管理間接部門活動】、Safety & Environment Management 【安全環境管理】. However, these eight pillars do not mean separating the different departments' responsibilities. Regardless of the pillar, the user, designer, and maintenance should work together to accomplish the goal. And the activity doesn’t have to be fancy. Instead, the important thing is to make sure that all related parties are at the Genba looking at the problem and exchanging thoughts and ideas. After all, none of the Japanese-oriented activity started in a fancy fashion. They just collected responsible people on the Genba.

Denso remains a strong process technology company. Every time they announce an interesting new equipment, I always wonder how maintenance has improved, too.


日本電装編. 日本電装25年史. 1974

日本電装株式会社社史編集委員会 編. 日本電装35年史. 1984.

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