Gemba Keiei Chapter 15: Just In Time

In this chapter, Taiichi Ohno talks about “just in time” but does not focus much on the material and information flow within TPS. Instead, he spends most of his time contemplating the English phrase’s origin.

The Origins of “Just in Time” in the Toyota Production System: Taiichi Ohno’s Theory

The Toyota Production System is based on two pillars: autonomation (jidoka) and “just in time.” However, I realized that “just in time” is a term that was created.

Taiichi Ohno proceeds to explain his theory that Kiichiro Toyoda took the English words and made a unique expression based on Japanese thinking. As a native English speaker, I find his theory on this matter to be questionable, but his thought process is interesting.

Taiichi Ohno writes:

“According to people from countries where they speak English such as America and England the correct phrase is “exactly on time”. The phrase “just in time” does not actually exist.”

He can’t be blamed for this misconception. This chapter was written in 1982. Even today, it’s not uncommon for English teachers in Japan to have questionable qualifications, just as it was in the past.

Understanding the Nuances of “Just in Time” According to Taiichi Ohno

Despite his limited English, Taiichi Ohno delves into the nuances of timing and the use of the words “in time” and “just.” He compares the use of “just” in the phrase “just a moment” to the Japanese word “chotto,” meaning “a little.” The main idea is that whether waiting or being on time, it’s important to do so for only a little amount of time and not too much.

Taiichi Ohno argues that the more appropriate Japanese word is “chodo,” meaning “just” as in “I just made it” or “just barely.” In other words, if you require material to be delivered after lunch, it should be delivered just around lunchtime, rather than in the morning or the day before. This still constitutes being “in time,” but not necessarily “just in time.”

He clarifies the misconception held by some English speakers who view Toyota’s “just in time” as requiring deliveries to be exactly on time, placing an unreasonable burden on suppliers. Ohno clarifies that if a delivery is required for use at 1PM, an 11AM delivery is acceptable, but a 9AM delivery is not.

At Toyota, a delivery made 2 hours in advance of the time of use allows for 1-2 hours of inventory, ensuring that new material is available by the time the line runs out. Therefore, “Just in Time” at Toyota is not about enforcing a 5-10 minute “exactly on time” delivery window and punishing suppliers for failing to meet it.

At the end of the chapter, Taiichi Ohno concludes that “just in time” is not proper English and that Kiichiro Toyoda coined the term to more accurately convey the Japanese concept of “chodo” or being on time.

The Evolution of “Just in Time”: Kiichiro Toyoda, Taiichi Ohno, and Shigeo Shingo

According to Toyota’s history, Kiichiro Toyoda is credited with introducing “just in time” to the development of the Toyota Production System in the 1930s. It was Taiichi Ohno and Shigeo Shingo who developed “just in time” into the system it is today, focusing on the three key elements of Takt Time, One Piece Flow, and Downstream Pull. While Kiichiro Toyoda had the original vision, it was Ohno and Shingo who built the framework and worked out the details to turn JIT into a reality, for which we are grateful.

As a matter of interest, Jules Styne wrote a song called “Just in Time” for the musical Bells Are Ringing in 1956. That was the same year in which Taiichi Ohno visited the U.S. on his study mission. It’s probably safe to say Ohno’s trip to the U.S. didn’t include a visit to the Broadway show.

*For a better understanding of the article, please refer to the Gemba Academy glossary.

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