Ohno on Flow
In Chapter 1 of his book, Ohno has a section titled “Establishing a Production Flow.” In Chapter 2, he punctuates this theme with another section dedicated to flow and boldly declares: “Establishing the Flow Is the Basic Condition.”
Flow is not some “oh by the way” thing. Ohno said flow is the basis of -- the foundational condition for -- the TPS. He was very clear.
I teach my clients the basic condition is “stable flow at takt.” Ohno and I are saying exactly the same thing. Ohno created and had in place an excellent quality system with stable flow at takt as a precursor -- and then built his quantity control system on top of that.
Today most managers either miss -- or simply ignore -- this reality and try to build a quantity control system on a weak foundation. They try to implement the so-called lean tools, such as heijunka, kanban and SMED, without first attaining stable flow at takt.
This approach is doomed to fail.
Why is this point so often missed? I am sure there are myriad reasons but to me the most obvious one is that most people who try to implement a lean manufacturing system never really created one, as Ohno did.
Rather, they try to get their knowledge of the elements and the implementation techniques from the literature and from consultants. Unfortunately, most of these consultants got their information from the literature as well, with a dabbling of implementation successes. And super-unfortunately, most of the information in the literature is written by academics who have learned the TPS by studying the TPS rather than living the TPS. To me, it is a little like taking advice about learning golf from people who have studied golf techniques and observed the experts; rather than from folks who have studied, observed and actually been on the course.
