Prof. Jeffrey Liker has uploaded an excellent slideshow from 2005 titled The Toyota Way: A Sociotechnical Learning Organization in Action. The image above is from this presentation in which Liker touches briefly on the kamishibai board and its use.
What is a kamishibai?
In Toyota’s system of jidoka or building quality in to each process, each person checks their own work. But this is not enough to guarantee 100% quality. It is a myth to think that “lean means no inspection” when in fact there are checks upon checks within a build in quality system. Kamishibai is an example of randomized as well as scheduled audits of those process checks and standards.
Among the visual management tools such as hour by hour boards, andon lights, gemba walks and shift-to-shift communication meetings which promote a workplace-focused lean management culture, the kamishibai system is lesser known. In fact the only complicated thing about it is the name, although from the point of view of the discipline required to actually use it, we could say that it is not a tool for lean beginners. The kamishibai board is particularly useful when there is a will and desire for managers to practice genchi genbutsu (go see what’s really happening) but they are unsure how to structure day or even what to do when they are on the shop floor. The kamishibai system formalizes, prioritizes and schedules the checks to be made on the gemba. It is a simple and flexible visual tool to ensure the required checks are being completed.
Why do we need a kamishibai?
The main aim is not to catch people doing something wrong. Before using the kamishibai an organization needs a healthy “why?” culture and not a “who?” culture. For a manager, the proper use of a kamishibai is to train your eyes to see problems (deviations from the standard), identify improvements while they are still small, and teach others to see and solve these problems. In the kamshibai system the process is just as important as the result. In other words, faithfully completing the audits is as important as the result of the audit itself. The purpose is not to find faults, although problems should certainly be made visible; the purpose is to get in the habit of checking each day.
How is the kamishibai used?
Team leaders and above also have the responsibility to check the work of others working within their team or span of control. The work itself and the checking must be based on standard work. The checks performed by the team leader are specifically to audit the line and the performance of the team members working there. The key areas checked include safety rules and the proper use of personal protective equipment, adherence to standardized work, maintenance of accurate documentation, general workplace organization, as well as whether or not other routine activities such as TPM (lubrication, cleaning and checking machines) is being done.
The team leader picks out a card at random from the kamishibai board. This randomness is important to prevent the checks from becoming predictable. If the checks followed a predictable pattern in theory it would be possible for the team members to defeat the system if they so chose, by following the standard during the check but not at other times. The person pulling the card reads the instructions for the corresponding daily, weekly or monthly check and goes to that process to perform the check. After the check, the card is turned over and returned. If there are abnormalities, these are noted on a problem board. A two-color system can be used to indicate that a problem has been found.
While the team leader audit is focused on their immediate work area or zone and the daily, weekly and monthly check cards are pulled on a random basis, the kamishibai process for the group leaders, area managers and above differs slightly. They have a wider span of audit (multiple lines or zones for group leaders, sections or department for area managers, etc.) and the timing of the cards and checks are based on a schedule. This schedule is built into the leader standard work which identifies when the supervisors and managers spend time directly on the shop floor during the day. The checks performed by the group leader tend to focus focus more on systems such as kanban, andon response, or hourly performance tracking. There may also be specific checks on critical to quality processes.
How do we get started with kamishibai?
A basic condition for starting to use kamishibai is that people hold each other accountable for following standards. Without this, don’t bother with kamishibai. This type of standard work for leaders is based on a longer cycle than an operator’s standard work but the goal is the same: insure that work is performed in the best known way for a safe, productive and high quality outcome. Although the cycle of checking may be longer, the response to nonconforming conditions should be swift and immediate. Needless to say, these countermeasures (action plans) should be made visual at the scene of the problem and the responsible persons must follow up frequently until the issue is resolved.
A site could have as many kamishibai boards as it has team leaders, group leaders and area managers (per shift). Within Toyota factories which use the kamishibai system there may be as many as 100 such boards. One of the keys to success is to pilot this system on a limited basis across several zones or a section, rather than the entire site at once, in order not to create an immediate and unreasonable pull on the managers to respond to and solve problems. The pull should be persistent and strong but not unreasonable. The condition of the kamishibai board will tell you not only how robust your processes are, but how well lean culture has become part of management behavior.