Due the magical number 7 (plus or minus two) it is useful to learn words that encapsulate an entire concept. In the software industry we attempt to do this with design patterns – squash a large concept into a simple word, like “observer” or “factory” – and it can be even more valuable when you can encompass a whole theory, principle or way of thinking into a word. Words like “agile” and “lean” are good examples of this, even though they get abused. If you are “doing Agile” but you don’t “look agile”, you probably aren’t really “doing Agile”.
Under the hood of Lean (which should always be lean) are a small collection of Japanese terms that successfully encapsulate key concepts. There are many, but here are seven key terms:
- Muda is waste. Specifically, it includes anything that is done that does not add value, including things that are done before they need to be done. There are seven kinds of waste (and these classifications can help you to see waste where it has been happily hidden for a long time).
- Muri is the principle of never overburdening the system or the people. To achieve flow, there must be slack in the system.
- Mura is concerned with properly loading a system and is related to reducing variability.
- A dramatic change intended to improve working methods.
- Continual small improvements to working methods.
- A signal to stop the line to prevent a defect continuing along the production line. In software, this is very often a build or test failure. All work is stopped until the defect is fixed.
- Automation with a human touch (also known as autonomation). Automation should be able to detect errors and shut-down to await human intervention.