Gemba Keiei by Taiichi Ohno, Chapter 31: There is a Correct Sequence to Kaizen

Taiichi Ohno explains in this chapter that there is a correct sequence to kaizen, and it is as follows:

1) Manual work kaizen
2) Equipment kaizen
3) Process kaizen

“Manual work kaizen means thinking of better ways of using the existing equipment. Rather than making tools (equipment), it is important to think of how the work should be done.” Quotes Taiichi Ohno. He points out that this gets harder as you introduce more modern, high performance equipment. Another way to say this is that it becomes easier to not think about the manual work, since the new machine seems so much faster and more efficient.

At ten Japanese pages this is the longest chapter in the book. Most chapters are in the five to seven pages range. Taiichi Ohno illustrates his point that there is a correct sequence do kaizen through examples including installing robots, using a high performance camera to take photos, buying and installing machines, multi-process handing, inspection versus built-in quality and seeing the true value added portion of work.

Ohno tells a story of when the Motomachi and Kamigo factories were newly built, and worker were moved to these factories they had new machines. It was actually a challenge to use these machines as effectively as the older machines which had a lot of kaizen (human wisdom) built into them. Ohno points out that it is easy to justify new buying machines that will appear to improve productivity and quality, but in fact this creates a temptation to let less experienced workers run these machines, which can create problems.

One could say that we are seeing some of this phenomenon today in the many recalls of Toyota vehicles, as a result of the rapid expansion, building of new factories, buying of new machines, and employing new workers to run these new and “better” machines.
Ohno points out that a very important part of doing step 2 equipment kaizen is having the skill and ability to kaizen the equipment. This comes from starting at step 1 and doing manual work kaizen, rather than simply specifying the newest machine, or relying on the machine tool manufacturer. This ability of Toyota to modify, specify, build and maintain machines on their own is an often overlooked hidden strength, one aspect of which is discussed in an interview by Art Smalley.

Step 3 Process kaizen is basically the sequencing of processes into an operation so that quality is built in rather than inspected in, features are created in a logical sequence requiring the minimum changes of tools, etc. Ohno says that it is important to start with manual work kaizen, which will result in ideas for equipment kaizen, which will result in ideas for process kaizen. The reality in most companies is that these are separate disciplines and not integrated or sequenced correctly.

Taiichi Ohno observes that outside of Japan the workers watch the machine while puffing on cigarettes, while in Japan the workers are made to do unimportant things just to keep busy. Multi-process handling is preferable to either of these, and that is why there is a correct sequence to kaizen that must be followed. Ohno ends the chapter by saying “Machine cycle time and manual cycle time are still mixed up, all over the world.”

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