For people who have worked at Toyota or companies strongly influenced by Toyota, the term "kaizen" is used more in the general sense, closer to philosophy than activity. The term jishuken is used to describe the intentional, workplace-focused activity we call gemba kaizen.

There is an important difference in nuance between jishuken and kaizen as it is understood as a part of Lean manufacturing (whether it be kaizen suggestions, kaizen events, or kaizen projects). During kaizen events my teachers would often yell "You must do more jishuken!" at the American managers after they had said or done something to demonstrate their lack of alignment with kaizen philosophy.

Translating this simply as "You must do more kaizen!" does not have the desired effect since to many senior managers, "doing kaizen" means sponsoring a kaizen team and showing up on Friday to review the results of the kaizen event. By calling for jishuken my teachers were demanding more self-study kaizen by the American managers.

I was told the origin of jishuken comes from "kanban houshiki bukachou jishu kenkyuukai" or かんばん方式部課長自主研究会 in the original Japanese. This translates as "kanban system department & section manager autonomous study groups". This was shortened to "jishuken" which is "self study". Jishuken is often called "autonomous study groups" in English.

In the early days of building TPS, Taiichi Ohno and others required the managers to get together on the factory floor to do hands-on kaizen activity. This began with department managers and section managers from the Motomachi and Kamigo factories getting together, selecting a particular "theme" and working on various process improvements. It may have been more cost-effective to let the engineers and supervisors do this sort of gemba kaizen, but the managers' hands-on involvement in kaizen helped them learn, take ownership and build a culture of genchi gembutsu at Toyota.

Because the kanban system was one of the starting points of the Toyota Production System, the jishuken concept began with kanban but it was soon and is today generally applied as a autonomous study group kaizen for the Toyota Production System itself. At many of the companies we visit on our Lean manufacturing benchmarking trip we call the Japan Kaikaku Experience, the primary kaizen initiatives are the suggestion system (all employees) and jishuken (managers). The suggestion system is applied to local, small, daily improvements and jishuken are projects linked to business goals and driven by teams of managers.

Last year there was an article about managers from North American Toyota plants being taken to suppliers to do jishuken. The reason given was that Toyota management realized that they did not have this experience and the managers did not know how to do or teach kaizen. One of the reason for this is that the Toyota Production System is mature and running smoothly at the Toyota plants in North America. Toyota had to take their managers out of their offices and to the suppliers to find shop floor problems to solve.

I think jishuken as it was originally intended is a very important thing. There is no way that Lean manufacturing implementation will succeed at an organization that does not have a clear operational model that they are working towards (the Toyota Production System), full participation and empowerment of the workers to make local improvements, and jishuken and other hands-on strategic kaizen activity by management. More companies are doing better with the first two.

For others it's too easy to say "our CEO's time is too valuable to be doing kaizen for several day". Perhaps, but how many hours of jishuken does a Toyota manager experience before they get to be CEO?