Editor’s note: This is an excerpt from the book, Management Lessons From Taiichi Ohno: What Every Leader Can Learn From the Man who Invented the Toyota Production System, by Takehiko Harada (McGraw-Hill Education, 2015).
The phrase, “kaizen equals getting closer to the final process” was hardly used by people at Toyota, which I think is why it stuck in my mind. It seems like a simple phrase, but many people have told me that it is confusing, so I will explain the background to the situation.
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When I was around 30 years old, I was working as an engineer in the headquarters machining plant. I was on the No. 3 truck undercarriage line. This line was synchronized with the main assembly line and supplied parts to it. The final process was to do a quality check, and sometimes that took a long time, delaying the delivery of parts to the main line and causing a stoppage. As a result, this problem was interfering with the stability of operations.
In order to keep the main line from being adversely affected by this, we moved the parts line to a shop next door and delivered finished parts to the main line. (Basically, we disconnected the subline from the main line and delivered finished parts to the main line.) As you might expect, we had solved the problem, as the line stoppages to the main line had ceased. When I reported this to Mr. Ohno on the gemba, he said, “Yes, we have fewer main-line stoppages, but the time required for adjusting on the subline has not changed. Kaizen equals getting closer to the final process. Now, however, it is further away.”
Our job as engineers was to find the reason for the variability in the process and change the conditions so that good product could be made in an environment that didn’t require lots of effort. Because production engineering couldn’t do this, we had just run away from the problem.
“If you lack skill, you can’t get closer to the final process.” How important it is to get the right conditions in place to make good parts. I felt that I had learned a fundamental truth about production at the time.
At the same time I thought how impressive it was that Mr. Ohno could see the real issue. I was also embarrassed. We had had no intention of running away from the problem, but the result of our actions had been to choose the easy way out, and to top it off, we thought that we had done a good job! “What are you guys doing?! Get it back to how it was before!” would have been an appropriate remark for Mr. Ohno to make, but his actual comment was more of a philosophical nature that really encouraged us to find the root cause of the variance and get the subline back to where it belonged—closer to the final process.
I think Ohno knew that our young group had done this without ill intent and felt that it was better to do something and fail than to do nothing at all. If you’re up at bat and you are going to strike out, it’s better to swing and miss than not to swing at all. Just by swinging the bat at the ball, you are going to gain some experience. We felt that we had learned a lot about kaizen when we struck out swinging.
When you think about it, the less inventory you have between processes, the closer you are getting to the end process. The same is true when you join processes. It was a simple sentence that had profound meaning for me. Ever since, I have asked myself and my staff to go check to see whether a change has gotten us “closer to the last process.”
Getting back to the point
There are a lot of so-called kaizen or improvement events out there that actually go further away from the last process. For example:
• Outsourcing the rework process to a vendor
• Outsourcing a deburring process
• Outsourcing the separation of good and bad parts to a third party
• Outsourcing the removing of the runner and gate (which are not required in the final part, but are necessary for the making of the molded plastic) from a molded plastic part
These are the worst offenders, but they actually happen quite frequently. Well, why is it wrong to give a process to a third party? Some people may say, “That party can do it at a lower cost than we can, so outsourcing it is a good thing.” The issue is that by keeping that process in-house, you keep the problem visible. If you see many people doing rework, it should motivate you to do something about it.
Things like burr-free casting and gateless molding come from the need to improve. If you cannot see the process, no one will think about it. The danger is that if something is difficult, it is outsourced; this then makes the company’s engineering weaker and in the end reduces its competitiveness.
I once had a big surprise when I studied the supply chain for a certain part that we used. This particular part involved four processes. Two of these processes were done locally, another was done on the island of Kyushu (1,000 km /600 miles away), and the fourth was done on a different island. My goodness! How much work in process did we have? I was convinced that it was at least six months’ worth. I am certain that this situation had a long history, but I think it was the culmination of purchasing asking over the years, “I wonder who can make it more cheaply?”
By having a shorter supply chain and bringing it closer to the last process, a company can be in better control in case problems happen.
The effect of Ohno’s “Get it closer to the last process,” or, in other words, “getting things closer to the assembly line is a good thing,” can be seen in Toyota’s history, where all processes that came under Ohno’s control as his responsibilities grew became closer to the last process.
The most important thing Ohno had in mind to reduce the production lead time was the concept of flow. When he was still the machine shop manager he noted, “We initially focused on reducing the changeover times and reducing the batch sizes” (from Ohno’s memoirs). He then continued, “We had people handle two of the same machines to increase productivity, but the batch sizes didn’t change. We then changed the layout to put the machines in the process sequence, and our batch sizes were significantly reduced.”
This did increase productivity, but in order to prevent overproduction, a downstream pull/replenishment system was incorporated. This was the start of the kanban method, which actualized the just-in-time philosophy.
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