The Order for Kaizen

Today I’d like to talk about kaizen—specifically, the order for kaizen. The term has come to mean “continuous improvement,” but kaizen originally translates from Japanese as “change for better.” To help clarify this useful concept, I’ll present three different views for approaching kaizen: Taiichi Ohno’s, Shigeo Shingo’s, and Hiroyuki Hirano’s.

Taiichi Ohno’s view (semi-strategic)

Taiichi Ohno is known as the father of the Toyota Production System (TPS). He has stated that there is a proper order for kaizen. This is:
• Sagyo kaizen (operations improvement)
• Setsubi kaizen (equipment improvement)
• Kotei kaizen (process improvement)

I believe that Ohno wanted to focus on developing the abilities of people first, since this is the lowest level where kaizen is possible. As Hirano says, “The starting point of manufacturing is always people.” Any production system should be people-oriented, and the first step of all kaizen is to raise the awareness of the people. This allows them to view the waste as a lean leader would. This is achieved only through operations kaizen. The operators involved find ways to make their work easier with what they have. Of the three types, operations kaizen involves the least amount of cost.

Ohno has said: “People with no capacity for improving operations are a problem because they like to buy new machines all the time.” And: “First improve operations. If you start out by bringing in the latest machines, people with no capacity for improvement simply end up being slaves to the machines.”

Next in line is equipment kaizen. Ohno challenges us to find new and creative ways of using the current equipment. “You must have the ability to tinker with and improve the machines you already have,” he advises. He recommends buying new equipment when you have made the maximum use of current equipment, and when it’s no longer possible to increase effectiveness without new equipment. Purchasing new equipment should result in an improvement of quality.

Ohno cautions against purchasing costly, specialized equipment and advises going for flexible and low-cost equipment. Without operation kaizen, equipment kaizen alone results in extreme waste. Now the organization can make waste much better, and a lot more of it. Machines can’t see waste, and they can’t improve anything on their own. Machine kaizen alone fosters status quo and invites complacency.

The last item is process kaizen. Ohno says: “Making things extremely well by turning the process upside down is process improvement.”

With process kaizen, you are looking at rearranging equipment or operations, changing layout, or improving the flow by linking processes.

Shigeo Shingo’s view (tactical)

TPS expert Shigeo Shingo has provided us with four targets for improvement. In their order of priority, they are:
• Easier
• Better
• Faster
• Cheaper

I was watching a Paul Akers (FastCap) video on YouTube, and I made a connection to what Shingo said. “Easier” is an improvement from the point of the operator. This should also mean that it’s safer for the operator to do; any improvement activity should first be focused on safety. “Better” is an improvement activity that improves the quality of the operation and/or product. “Faster” is an improvement activity that increases efficiency. The final target, “cheaper,” should be the least critical of the improvement activities because kaizen’s goal isn’t necessarily to focus on making a process cheaper.

Hiroyuki Hirano’s view (strategic)

Hiroyuki Hirano is a prolific author of several books on the Toyota Production System, including 5 Pillars of the Visual Workplace (Productivity Press, 1995) and the JIT Implementation Manual. (Productivity Press, 2009). He describes four types of kaizen:
• Point kaizen
• Line kaizen
• Plane kaizen
• Cubic kaizen

Point kaizen is similar to operations improvement. This is basic, incremental improvement activity at the operations level. Next is line kaizen. This is where many point kaizen activities merge to create flow manufacturing, such as in an assembly line. Hirano calls this a vertical development. This is akin to selecting a model line and transforming it to make the process flow better. Once we have line kaizen, the next progression is through plane kaizen. This is the concept of yokoten, or horizontal deployment, and is where ideas and learning from the model line are used to create more model lines across the plant. Thus, plane kaizen results in horizontal development. The final level, cubic kaizen, is where improvements are made across multiple departments and even the enterprise’s supply chain.

My thoughts

As with any other buzzword, kaizen has come to mean many things. My goal here has been to provide a little more structure to the wonderful idea of kaizen. I would encourage the reader to also read my previous post on this topic here (“A Brief Look at Kaizen in Light of the Toyota Way”).

I’ll finish this off with a great story about equipment kaizen from Hitoshi Yamada, a student of Ohno, which I read in Yamada’s book, Forging a Kaizen Culture (Enna, 2012):

“Yamada was at a large component manufacturer, Stanley Electric’s Tsuruoka plant. They were looking at a machine that assembled extremely small light bulbs. The cost of the machine was $150,000. The machine had two turn tables and several robot arms. Due to the high cost of the machine, the factory manager felt that he should rely on mass production to make the maximum use of the machine.

“Yamada told the manager to study the machine and find areas of wasted movement. And even better, to build a smaller and better machine.

“This improvement activity took several weeks of trial and error. The final machine was $5,000 and 1/27th the size of the old machine. Since the machine was much smaller in size, it was also more efficient.”

Always keep on learning....

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