Language serves to both define and set apart knowledge communities. Just about every discipline has its "lingua franca" - the terms and phrases that mean something very specific in that discipline. The frustrating thing for anyone from the outside is hearing the terms and either having no clue, or understanding them in some other context. I see it happen in areas where I have some expertise - or when I visit new arenas.
It should not be surprising that my reading of more material in the Lean community is causing some of that friction for me. I've recently finished Womack and Jones' Lean Thinking and found myself noting all the Japanese terms that they use (and define) throughout the book. I am not sure whether the use of these terms is a good thing or bad thing. They clearly mean something very specific, but their translation and use (over-use?) can become overwhelming.
So, for what it's worth here is my abbreviated Lean glossary with some notes. They are in the order I wrote them in my notes, rather than alphabetical or any other ordering.
- muda: waste. I've seen this term in enough places for it to be familiar. Waste in the delivery of a product or service - the elimination of it - is a cornerstone of Lean implementations. And it is an area of some conflict with Theory of Constraints, which suggests focusing only on those areas which are constraining delivery.
- kaikaku: radical change to create improvement. This is a big, step-change in operations that is often done at the beginning of implementations. This is the brother of kaizen, the more familiar term.
- kaizen: as commonly used, this means continuous or incremental improvement. People talk about kaizen events and frequent kaizen-ing of a process. I like the explicit emphasis that things must continually improve.
- kanban cards / boards: signal cards that indicate it is time to take some action. In the Lean community, kanban cards are a key element of the pull mechanism that gets created. Consume one part at operation X, and send a card back up the line to signal operation X-1 to produce a replacement.
- takt time: the time required to produce each product, given the current demand. This is one that I don't completely understand yet, as the takt time can change, depending on the demand - it is a pull-based value. I think I understand it as a form of cycle time, but there is a stronger connection to the full value stream.
- andon board: a mechanism to stop production when problems are noted. The goal being that errors are noticed and corrected as quickly as possible. Based on the way it is described elsewhere as a status board, I am not quite sure how this differs from a kanban board.
- heijunka: level scheduling. This is the means by which market variability is smoothed in the plant. Another area I understand at the high level, but I am not sure why it needs a special term.
- poka-yoke: making an operation or process mistake-proof. This is particularly important if an operation often causes line stoppage (via the andon board?) or other production problems.
- sensei: master or teacher. This is a common enough term within popular culture. In the book, the authors strongly recommend that Lean implementers find their sensei to help implement as well as to be someone who can act as a sounding board.
- chaku-chaku: load-load. This is a specific type of operation where one operator manages multiple operations on a part, loading it on and off multiple machines: thus the load-load of this term.
There are many, many other Japanese terms used in Lean Thinking and found in the glossary. But these are the ones that stood out for me. Interesting.
[Photo: "Coffee Language [4:365]" by Michael Daines]