"Muda" is Japanese for waste. But in manufacturing, and increasingly in service, "muda" is a more powerful word than waste because it has come to be associated with the set of 7 wastes, with kaizen, with Gemba, and with JIT or "world class" in general.

Taiichi Ohno, father of the Toyota Production System, of JIT, and patriarch of Lean Operations, originally assembled the 7 wastes, but it was Deming who emphasised waste reduction in Japan in the 1950's. Today, however, it is appropriate to add to Ohno's famous list, presumptuous though that may be. The section which follows begins with Ohno's original seven, then adds four "new" wastes.

Waste is the opposite of value. So as another dimension to the waste categories, one can think of different types of waste:

• Process waste (for instance changeover time, SPC, planning, evaluation, etc) which are currently necessary for the process, but do not add to customer value. Such activities are temporarily necessary waste. Aim to reduce then eliminate.
• Business waste (for instance, it benefits managers, employees, suppliers). These too are waste, and need to be critically examined for efficiency or elimination.
• Pure waste, which should be eliminated as soon as possible.