Muda (Japanese term)

Muda (無駄, on'yomi reading, ateji) is a Japanese word meaning "futility", "uselessness", or "wastefulness",[1] and is a key concept in lean process thinking such as in the Toyota Production System (TPS), denoting one of three types of deviation from optimal allocation of resources. The other types are known by the Japanese terms mura ("unevenness") and muri ("overload").[2] Waste in this context refers to the wasting of time or resources rather than wasteful by-products and should not be confused with waste reduction.

From an end-customer's point of view, value-added work is any activity that produces goods or provides a service for which a customer is willing to pay; muda is any constraint or impediment that causes waste to occur.[3]

There are two types of muda:[4]

  • Muda type I: non value-adding, but necessary for end-customers. These are usually harder to eliminate because while classified as non-value adding, they may still be necessary.
  • Muda type II: non value-adding and unnecessary for end-customers. These contribute to waste, incur hidden costs and should be eliminated.[5]
  1. ^ Kenkyusha's New Japanese-English Dictionary, 5th edition, 2003, Tokyo: Kenkyusha, p. 2530.
  2. ^ Emiliani, Bob; Stec, David; Grasso, Lawrence; Stodder, James (2007). Better thinking, better results: case study and analysis of an enterprise-wide lean transformation (2nd ed.). Kensington, Conn: Center for Lean Business Management. p. n11. ISBN 978-0-9722591-2-5. Retrieved 4 March 2023.
  3. ^ Kato, Isao; Smalley, Art (2011). Toyota Kaizen Methods: Six Steps to Improvement.
  4. ^ Lean Enterprise Institute, Waste, accessed 3 February 2018
  5. ^ Sayer, Natalie; Williams, Bruce (2012). Lean For Dummies 2nd Edition.