The origin of "Kanban"

https://www.hmoperationsmanagement.com/post/the-origin-of-kanban

Kanban is an important tool of the Toyota Production System (TPS). In TPS, it is written as かんばん?or カンバン. The first is written in Hiragana, and the later in Katakana. There is a specific reason to write differently. Hiragana means “necessary” Kanban, while the Katakana means “unnecessary.” It is a unique way for TPS to create self-reflection about whether we need this Kanban.

In typical Japanese, Kanban means signboard. When I initially heard the word Kanban, I didn’t think of a small piece of paper attached to a box. I thought it would be a huge signboard. TPS is confusing for a typical Japanese.

Kanban is written as 看板. This is a phonetic Kanji. People started using this from the Edo era (1603-1867). The second symbol means the board. The first symbol 【看】means to diagnose carefully. The upper part of the symbol represents the hand, and the bottom part represents the eye. The Japanese in the Edo era probably liked this symbol better than the original one because they wanted the people to see the signboards with attention.

The original Kanban was written as 簡板. The first symbol 【簡】means simplified. They say that people started using it in the 14 century. People started to use symbols on the signboard as literacy rates increase. Another reason was that Samurai and nobles started to use family logos. They print those logos on a simple board to be posted.

Before this simplified version, there was a complicated version. That was called “Hyou.” It was complicated because instead of letters, product pictures were drawn on it. In some cases, they placed samples on the board. Or the board itself was the shape of the product. Some government documents dating back to the eighth-century state that the market (or store) must post these “Hyou.”

This “Hyou” is written as 【標】. This is very strange symbol. The left side means the tree or the wood. The original version of the right side meant hands holding a neck on a fire. It is a very strange symbol as many academics are confused on how such shape holds a meaning. (The current 標?looks more like paper but thats modified version.) But, we started to use as a sign, target, which represents the borderline between somethings in some unique shape. For example, when you go to a Japanese shrines, they will have a huge rope across the main area. That rope is called “Shimenawa” and written as 標縄. It is the rope that represents the borderline between God’s territory. Also, a typical Hyou always had some real shape, like the rope. The original sign boards had samples attached to it (and that’s why the simplified board was invented). Specimen in Japanese is 標本, book of Hyou. There’s always a Genbutsu or real thing that represents it sign. [The symbol has more meanings. This is just one of them.]

This symbol is used in standardized work 【標準作業】. Or standard 【標準】. Standardized work represents good work and it is not theory, it is real. Standard represents what is good or bad, but it shouldn’t be just paper. It should be real. In some place, I ran into a book of “defects,” which helps us understand the standards better.

And the fact that Kanban original symbol is used as part of standard imply us something important. The two concepts are not separate but like an identical twins.

Today, when we go to factories, many claims that they have implemented Kanban. But at the same time, standards are violated or standardized work do not exist. How is that possible? There is a clear missunderstanding there. Kanban should not and will not function under conditions where standards are missing or violated. Six Rules of Kanban, which Ohno described, are simple rules. When an organization do not respect other rules, such as safety or quality, violating the simple Kanban rules will be nothing.

I don’t know if Ohno or the first generations of TPS knew about the origin of Kanban as Hyou【標】. But it turns out that creating a continuous flow of Hyou is what makes this system. We define, follow and improve work standards and standardized works. The permission to start a work is represented by Kanban. And, all these things are not just paperwork. It something that is created, followed and improved at Genba. Yes, we draw work standard and standardized works on paper. Kanban is paper. But there is this connection with reality. Disrespecting this connection is a huge crime. Also, the flow of how we document follows the history. There is this Genbutsu that is important. We draw a picture or words to simplify. Then we try to visualize.

At least, please remember that Kanban is part of a system, not an independent tool.