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Inoue’s “Work Study”

In searching for the book that Taiichi Ohno read to start the Toyota Production System implementation journey, I ran into an author. His name is Yoshikazu Inoue.

Inoue wrote several books on the “Standard Work” before 1938, when Ohno started the search. What made me interested is his focus on the “Work Study.”

My hypothesis. One of the gaps of understanding that exist is caused by this “Japanese interpretation of Standard Work.” The key word is “Work Study.”

Why Inoue?

When I researched the National Diet Library of Japan’s database on books for “Standard Work” published before 1938, when Taiichi Ohno started his research, there were 16 books listed. There are possibilities for other books. But for this post, I focused on those 16 books. Out of those 16, two books were written by Inoue, and one of the titles of the book grabbed my attention.

Yoshikazu Inoue was working in a train factory. He was introduced to Scientific management thinking through the novel “Secret of eliminating unnecessary steps.” In 1919, he traveled to the USA to study Scientific management. When he returned after three years, he joined the Association of Osaka Efficiency.

Inoue wrote several books, and two books about “Standard Work” before 1938 got my attention. The first book is “Scientific Management for Technologists,” written in 1927. It is a bit “old,” but the title looks attractive for Taiichi Ohno since he was a mechanical engineer. At the time (1938), the interest in “Standard Work” came from accounting. This makes sense since Ohno got the challenge about “Standard Work” from his boss, Taizo Ishida, who was responsible for the cost. Half of this book is about the need for Japan to develop more people with scientific management. I am not sure Inoue meant “engineer” or “manager.” This was written before those became two separate words in Japan; he probably meant hybrid.

“Work Study”

The second book, "Practice of management engineering efficiency life and work rationalization,” was published in 1933. Out of 260 pages, almost 200 pages are about “Standard work.” (The first book only had ten pages.) The major difference is the “Work Study.”

“Work Study” is not a Japanese invention. Around 1930, it appeared in the USA. My understanding of the work-study is time study (Taylor) plus motion study (Gilbreths). But Inoue’s work-study is a study of work at the shop floor before conducting a time or motion study. And his focus on this topic is radical. Out of 200 pages on Standard Work, he spends the first 100 on “Work study.”

In these 100 pages, he highlights the need for standardizing every aspect of work.

Here are some of his topics;

  1. Labor Characteristics; right hand or left hand, vision, knowledge, attention, memory, response, emotion

  2. Air; temperature, humidity, airflow

  3. Light; Natural or artificial, direct or indirect, area or spot

  4. Noise

  5. Vibration

  6. Dust

  7. Gas

  8. Raw materials

  9. Posture; Stand or sit

  10. Machine

  11. Tools

To some degree, I think Inoue is over-standard. (Like he talks about how blood type impacts habits.)

As I read, I thought about Inoue’s framework on “Standard work” and how Ohno (and Toyota) developed their standardized work.

Taiichi Ohno’s Toyota Production System starts with the three elements of standardized work (Takt time, Work sequence, and Standard in-process stock). But why did he not mention the work standard? He and Toyota considered those as common sense since they read in outside publications (like Inoue). But just working on Standard work charts and Combination tables doesn’t necessarily lead to results because of problems in quality, stability, etc. Many of Toyota’s Standardized Work prerequisites are missing, typically covered by Work Standards. I felt that the gap would close if we knew there was Inoue's (or Japanese) misunderstanding or interpretation of "Work study" between the history of evolution from Scientific management to TPS.

This Inoue’s publication is also a warning. He mentions Taylor and Gilbreths, but which part is his original is unclear. This method is common even today. Ohno is mentioned in the first chapter, but the rest differ completely. I’m not saying we can’t change. We need to be clear on what we change and why. (And yes, Ohno cut several things, like fatigue calculation, by Inoue. He exchanged that math with team leaders and Andon.)

Inoue continued his proliferation of efficiency improvements in a monk style after. He lived until 1971, so he should have heard about Toyota Production System but that time, but there are no remarks from him. I guess that he was happy to see such an example.

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