Muda - Japanese term for waste. The concept comes from lean manufacturing (TPS) as applied to management improvement.
delineated 7 distinct types of waste:
- Defects - improve the process to reduce errors: SPC, poka-yoke etc.
- Overproduction - producing what is not needed. This waste is address with pull systems, just in time inventory etc.
- Transportation - producing as close to the customer as possible reducing this waste
- Waiting - time when people must wait to engage in productive activity
- Inventory - just in time inventory reduces this waste
- Motion - elimination of any excess motion needed to add value is the goal
- Processing - optimize processing to eliminate as much work as possible
Muda is anything that doesn't add value to the customer. Some muda is inevitable the goal is to reduce it as much as possible and continually reducing it over time.
Book: Toyota Production System
: Beyond Large-Scale Production by Taiichi Ohno