(EN) On the Lean Guru Shigeo Shingo

Shigeo Shingo is a name that everyone in the United States lean community knows. He is sometimes considered „the world’s leading expert on manufacturing practices and the Toyota Production System,“ an „engineering genius,“ and the foremost guru of lean production. Some sources even claim he invented the Toyota Production System and taught Taiichi Ohno. Shingo greatly helped to popularize the idea of Lean in the USA. However, he invented much less than what is sometimes claimed, and there is also quite some disagreement in the lean community on this. Let’s have a look at his life and his achievements.

The Beginnings

Born in Saga City, Japan, in 1909, he graduated from Yamanashi Technical College with a degree in mechanical engineering. Afterward, he worked as a railway technician in Taipei during the Japanese occupation of Taiwan during World War II. As the war ended,  so did his Job in Taiwan. Shingo then became a consultant at the Japan Management Association (JMA) at age 34. In this position, he gathered experience at Mazda and Mitsubishi Heavy Industries.

Shingo and Toyota

In the 1950s, he was contracted by Toyota for a basic industrial engineering skill training, the „P-Course“. He did not develop the course himself, but was one of the first people trained in it in order to train others (train-the-trainer). This was part of Toyota’s effort to update their Training within Industry (TWI) courses. TWI was a US program for training workers and improving quality. Highly successful during World War II, it lost a lot of its steam in the US after the war ended, but it became popular in Japan. Shingo was contracted to update the „Job Methods“ section of TWI (afterward called P-Course). He also taught classes on time motion, a well-known method originating with Taylor and Gilbreth in the US.

Between 1950 and 1970, Toyota developed a method to reduce changeover times. Many different employees at Toyota, including Taiichi Ohno, were involved in this. Shingo was involved only towards the end of the program around 1970, when he was contracted to do a class on quick changeover methods. This class helped improve the changeover of one of the last machines that were not yet improved. To repeat, he participated in only one quick changeover workshop at Toyota!

It was at this time that Shingo became more interested in the Toyota Production System. He learned what he could about it and constantly tried to schedule meetings with a more and more reluctant Taiichi Ohno. From Ohno’s point of view, Shingo wanted to have academic discussions, whereas Ohno was only interested in practical applications.

In 1980, Shingo published a book on the Toyota Production System. This publication was to my knowledge without consent of Toyota, and he no longer did any trainings at Toyota afterwards. He did visit Toyota plants, and also worked for other companies in the Toyota group, but overall the relationships seemed to have cooled down.

Shingo, the „Inventor“ of the Toyota Production System

Afterward, Shingo moved to the United States. In 1980, the West was just starting to realize the power of the Japanese automotive industry, as it outperformed the US industry in both quality and cost. There was much demand to understand what enabled this Japanese superior performance. Unfortunately, due to the language barrier there was little information about the secrets of the Toyota production System.

Shingo was one of the few sources in the United States–if not the only one–who knew about the Toyota methods first hand. As such, he had a very fast rise to industry stardom. The main driver behind Shingo’s rise to stardom was Norman Bodek. When re-publishing Shingo’s book through Bodek’s publishing house Productivity Inc. the title changed from the (Japanese) Toyota Production System to the (English) Shingo System. Bodek also (in his own words) „started the Shingo prize and got him an honorary doctorate degree from Utah State University„.

Since then Bodek praised Shingo at every opportunity, calling him „absolutely brilliant, probably the greatest  manufacturing genius of our time, able to solve every manufacturing problem presented to him„. It seems that mainly through this successful promotion Shingo got the (in my view incorrect) reputation as the primary inventor of the Toyota production system. Bodek translated many more books of Shingo, always with Shingo having a prominent position in the development of the Toyota Production System. For example, in one book he included a timeline of industry events. Shingo was placed on this timeline a whopping eleven times, claiming to have developed the theory of flow layout, introduced scientific thinking, developed quick changeover, introduced pre-automation, and invented poka yoke and the non-stock production system, to name just a few.

His fourteen books are still bestsellers in America. If you can read Japanese, the original Japanese books are much cheaper or even out of print due to low demand. Japanese lean experts who read his books considered them mediocre when compared to the literature available in Japanese and overall very poorly written. Shingo did not claim that he invented the Toyota Production System in his Japanese books.

He also claimed that he invented numerous things related to lean manufacturing as well as the Toyota Production System. This claim is based on a presentation for the Japanese Management Association in 1946, which is now lost in history, and its content can no longer be verified. Or, during a project at Matsushita Electric, he installed conveyor belts for the transport of parts. He re-coined this as a new invention, the Mikuni Method. In reality, there was not much new about conveyor belts, and the method is now all but forgotten. Even most lean experts have never heard of the Mikuni Method. Overall, I think this is unfortunate. While I have never met Shingo himself, people that did meet him described him as a very humble person.

The Legacy of Shigeo Shingo

Shigeo Shingo did not invent the Toyota Production System. He also did not invent the method of SMED. What he did was bring its knowledge to the United States and popularize it there. And that by itself is also a major achievement! He provided first experiences in the Toyota Production System in the USA (he is less known in Europe). Thousands of people learned about Lean Manufacturing from him. He coined key terms used in lean manufacturing (for example, SMED for quick changeovers or Poka Yoke for mistake proofing). The Shingo Prize for Excellence in Manufacturing is one of the most prestigious awards in the industry, considered the Nobel Prize of manufacturing. For these achievements he is rightfully praised. However, he also seems to have claimed many more contributions to Lean than what he really did. For me this is unfortunate, since in my opinion there would have been no need for such additional self promotion. Being the first to bring the knowledge to the US would have been more than enough for his rise to stardom. In any case, the methods he taught are good, so please go out and use them to improve your industry.

Addendum

The question of Shigeo Shingo’s contribution to TPS is a hot topic for discussion. Many US lean experts rush to defend the honor of Mr. Shingo. But also other US experts question his contributions. Overall, the views are often mixed. My main but not my only outside source is Art Smalley, but I also talked with my contacts within Toyota.

• Smalley, Art. “A Brief Investigation into the Origins of the Toyota Production System.” Art of Lean, July 2006.
• Smalley, Art. “A Brief History of Set-Up Reduction: How the Work of Many People Improved Modern Manufacturing.” Art of Lean, 2010.
• Isao, Kato. Shigeo Shingo’s influence on TPS – An Interview with Mr. Isao Kato. Interview by Art Smalley, April 2006.
• Kevin Meyer: Much Ado About Shingo and Ohno.
• Mark Graban: Is Shingo overrated?

Please be aware that some of them have gone off-line since I posted this article, but googling may provide copies in some odd corners of the web. In any case, Smalley’s findings are consistent with my own experience in Japan and Europe, and also with my discussions with Toyota employees. There are also some good overview discussions about the resulting conflict between supporters and critics: