Toyota Change Point Management: Henkaten

Henkaten is an approach by Toyota to deal with changes in their manufacturing system. It is one of the lesser-known words of the lean vocabulary. Often translated as “change point,” it is about managing a change. However, there is no magic behind yet another Japanese word. It is all just the basics like most methods in lean manufacturing: attention to details, standards, and visual management. Let me show you!

Linguistics… and This Is a Bit Confusing, Sorry…

The word henkaten (変化点) consists of henka, which has almost the same meaning of change, variation, alteration, mutation, and transition; and ten (点) for point, spot. The very similar henkoten (変更点) consists of henko (変更) for change, modification, alteration, revision, and amendment; and again the ten (点) for point, spot. In fact, many translation engines translate both 変更点 and 変化点 as “change point” or just simply as “changes.”

However, while both words describe a change, they have slightly different meanings in Japanese. Henkaten is a change that was not really initiated, but just happened. Henkoten on the other hand is an active change, where you (or someone else) actively changes something.

Toyota’s henkaten is a method for how to deal with such not-actively-initiated changes… but also includes changes that are actively initiated. Henkoten, however, is also often connected to manufacturing, and can be related to continuous improvement (kaizen). Some English presentations on henkaten confusingly show the Japanese characters for henkoten as an illustration. However, I have the feeling that even many Japanese are sometimes befuddled by the very similar henkoten and henkaten. As for us, we just follow Toyota and call it henkaten, or, to make it more readable, change points.

Identify Change Points

Henkaten refers to change points or change management. Usually this is seen through any of the well-known groups of man, machine, material or method, often also including measurement and mother nature (the best word we could find starting with “M” that stands for the environment). The first four Ms are commonly used at Toyota in connection with henkaten.

  • Man: Are there upcoming changes in personnel where a new member joins, someone gets trained in a new process, or a person leaves the group? Is there a shift change or generally the start of a new shift?
  • Machine: Are there changes to the machine? Will a new machine be installed? Is an existing machine refurbished, or taken out of the system?
  • Material: Any changes in the material? Are we switching suppliers, or is the product design switching to a new material? Do we switch from one product to another product?
  • Method: Are there changes in the method? Is there a change to the work standard?
  • Measurement: Are the testing requirements updated? Are the tools re-calibrated? Are there new tools?
  • Mother Nature (aka Environment): Has something in the environment changed? Is it hot/cold/dry/wet today?

Effect of Change Points

Such change points are relevant because changes are fundamentally fluctuations (muda). After a change in any of these aspects, it is possible that safety, quality, speed, or cost will worsen. At Toyota, the focus is usually on quality, since this is most likely to be impacted by a change in the system.

Manage Change Points Using Work Standards

This change point management is different from the normal daily management. If the line is running normally, you just need to keep it running. However, if there are changes, especially in the 4M (or 6M) man, machine, material, method, measurement, and mother nature, you need to be on the lookout for abnormalities and problems caused by this change.

Such change management is best done using a work standard. You’re all familiar with SMED, where the change point is of the type “machine” and the machine and its tools are changed over to a new product. A changeover standard helps to make the changeover fast and smooth, and to make the machine perform well right from the start.

But standards can also be used for other groups. I had one plant where ten workers were working in a tight space supplying material to a large machine. Always after a shift change, problems increased because the workers had to coordinate themselves again. The solution was a standard where not all workers were changed at the same time, but in one-minute intervals. Hence, the worker had some time to absorb the rhythm from his already working colleagues, instead of being surrounded by nine other equally clueless colleagues.

Manage Change Points Using Visualization

It also helps to visualize the change point. Use colors, labels, and any other tool from visual management that suits you. Toyota sometimes uses a change management board. There are different types of boards in use. One is a simple list, where each change is categorized as man, machine, material, and method, or even also measurement and mother nature, its machine/line/work order is listed, and the upcoming change is detailed.

Another possible board shows all machines or processes as boxes. Colored magnets are used to indicate a change in man, machine, material, and method or even also measurement and mother nature. A color-coded magnet on a machine or process alerts others to pay particular attention to that machine to ensure consistent performance is maintained.

Yet another option is to have a separate color for rush jobs, to visualize tasks that popped up suddenly. For example, when producing parts, a rush job is more likely to have a lack of material or missing tools. For projects, a rush job is more likely to miss information needed to proceed.

Similarly, changes in delivery dates, arrival times, order sequences, order quantities, or other changes can be visualized.

Overall, henkaten is a nice way to learn how Toyota manages changes. The idea behind it is not fundamentally new, it is just attention to details, standards, and visualization. But it does reduce fluctuations due to changes in the system! Now, go out, identify your change points, manage them, and organize your industry!

All About Work Standards Cover Ebook ENGLISHPS: I just completed my new book All About Work Standards: Creating, Implementing, Maintaining, and Improving Work Standards, Toyota Standard Work, and Leader Standard Work for Continuous Improvement. Read more about it here.

Sources

One particularly good source on henkaten was “Toyota’s Change Management for Improving Production Management: How to Proceed, Examples, and Tools” (産管理力を高めるトヨタ流の変化点管理とは~進め方と事例・ツール), in Japanese, by former Toyota manager Junichi Matsui (松井 順一).

 

 

 

 

 

 


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