There is one word that currently takes the lean world by storm: kata, or more properly Toyota Kata, a method developed by Mike Rother. The idea behind it is not only a bunch of buzzwords (like all too often) but actually goes in the right direction. Overall, I like the concept, although the attention it gets sometimes feels overdone. Let me give you the gist of kata.
Kata (型 or 形) is a Japanese word that literally means form, model, pattern, type, style, or mold. It is most often used in the context of Japanese martial arts (judo, kendo, aikido, and karate), but also in Japanese theater and tea ceremony.
In karate it is one of the three basic exercise types. The first one being Kihon (基本 or きほん for foundation or basics), for basic ways how to stand. The second being Kata, a choreographed set of movements that are repeated over and over again. This will improve muscle memory. Finally, Kumite (組手) is free sparring with an opponent. As such, kata is a very good name, since the method proposes regular repetition of the same five questions. Below is a video of the 2016 World Karate Championship male team kata competition.
Hence, Mike Rother used the word kata for his approach. Since it is modeled somewhat based on Toyota, it is usually called Toyota Kata, to distinguish it from the martial arts kata. However, the term itself is to my knowledge not used in that form at Toyota.
What Problem Does Kata Try to Solve
Most lean methods and tools aim to improve individual aspects of manufacturing (and other) systems. Kata is an overarching approach that helps keep track of the overarching goal and work toward achieving it.
In my view, this is often a significant issue, and one of the major reasons why so many lean implementations fail (the other being a lack of PDCA, especially the C&A part). Lean projects are often started for reasons like
- they can be done
- it has a nice buzzword
- it was in the last book I read on management
- someone else is doing it
All of these are not really good reasons. They lead to meandering your way with aimless improvement. You improve something (assuming you get the PDCA part right), but it may or may not contribute to your overarching goal, or in worst case even be detrimental to the overall goal. You may not even have an overall goal. And, as Yogi Berra said, “If you don’t know where you are going, you might wind up someplace else.”
As such, I see this as an approach that addresses one of the most significant issues in lean (or in manufacturing in general).
There are actually two separate kata. One is for individuals who want to improve the current situation, the Improvement Kata. Another one is for other individuals who want to coach and teach others in the way of kata, the Coaching Kata. Let’s start with improvement kata.
The improvement kata helps you get from your current state into the direction of the vision (or true north) through many different small steps. Below is a visualization of the improvement kata, based on Mike Rother’s book.
Steps of the Improvement Kata
Actually, kata starts out by defining the vision. This is the direction where you ultimately want to go. You may or may not actually reach this vision, but it is necessary to clarify the main direction. For Toyota, Mike Rother interprets these visions as follows (source at the end of the post):
- One-piece flow: I totally agree. See also my post Toyota’s and Denso’s Relentless Quest for Lot Size One.
- 100% value add: Good vision.
- Security for people: A bit too vague for me. I would replace this with Respect for humanity.
- Zero defects: Okay-ish as a vision, just don’t use it as a target.
Next you need to understand your current condition, where are you now.
The third step is to develop the target condition based on the current condition and the vision. These target conditions should be not too easy to do, but still feasible within a time frame of a few weeks or months. The (currently) impossible part is the vision, and through many small steps we move toward the vision. Mike Rother distinguishes between target condition and target. A target is an outcome (e.g,. x pieces per hour, defect rate below y%, etc.). A target condition is a description of a process or system. How should the future system function and operate.
Finally, in the last step you can work on finding a way from your current condition to the target condition, overcoming the problems and obstacles in between. This includes a whole lot of problem-solving approaches, and may include some of the more familiar lean tools like kanban or SMED. Here you should also definitely use PDCA!
The Five Improvement Kata Questions
Mike Rother summarizes the improvement kata in five questions, which you should repeat regularly during your improvement process (again, source below). The repetition of these questions is the actual kata in the Japanese sense of the word. The vision is not questioned repeatedly, but changed very rarely once established (think decades).
- What is the target condition?
- What is the actual condition now?
- What obstacles prevent you from reaching the target condition? Which ones are you addressing now?
- What is your next step (your next PDCA cycle)?
- Where can we go and see what we have learned from taking that step?
Please note that these improvement kata questions are usually called “coaching kata” questions. They will be used again for the coaching kata:
The improvement at Toyota is done by the operators themselves, and by their supervisors and managers. The operator improve lots of little things, but the bigger potential is from the supervisors and managers (raising 90% of the productivity improvement according to a paper by Koichi Shimizu, source below). They do improvements and also teach and coach others.
The coaching is (unfortunately but definitely) not a group activity. Rather, it is one mentor and one (or very few) mentee(s) who are coached individually one-on-one. So don’t even think about a mass “kataing” of your people in a few classroom lectures.
The goal of a coach is also not to simply give the answers. This way the student would not learn, and also the improvement would be limited to the ideas of the coach. In many cases the coach does not even know the answers.
The coaching is done in regular intervals (maybe weekly) with a duration of around twenty minutes (or as needed). These meetings are also based on the five kata questions from above. Basically the coach goes through the five questions, listens to the answers, and gives his input. An A3 sheet can also help with the meeting, as well as doing it right where the issue is (on the “gemba“).
Too Much Kata…
One thing I definitely don’t like is that it is turning into a new “religion” within lean. There are about 17 million results on Google for Toyota Kata, of which 1.3 million offer or mention a Toyota Kata training. Books promise you “Superior Results in 20 Minutes a Day.” Overall, kata has turned into a big business.
While I understand that ringing the bells is necessary to sell your idea, I am not overly fond of it. I also worry that the promotion and training of kata has overtaken the actual improvement process. I am not sure if a ~3-hour online Toyota Kata course really prepares someone to be a coach, and I doubt the credentials of the 10-hour kata certificate (links intentionally omitted).
These trainings are fine, as long as you understand that these are only a bare-bones starting point, and true skill comes only from practice. And again, the overall concept behind kata is sound and valid. If you want to continue with kata, I can recommend Mike Rothers book Toyota Kata: Managing People for Improvement, Adaptiveness and Superior Results. Now, go out, coach your people using these five questions (or along the line of that), and organize your industry!
Mike Rother: Toyota Kata: Managing People for Improvement, Adaptiveness and Superior Results, McGraw-Hill, 2009.
Shimizu, Koichi 2004: Reorienting Kaizen Activities at Toyota : Kaizen, Production Efficiency, and Humanization of Work. 岡山大学経済学会雑誌.