Three distinct wastes — futile work, uneven flow and overburden — where removing one can create another.
Toyota's practice separates what Western efficiency drives usually merge. Muda is work that adds nothing; mura is variation in flow; muri is loading people or machines beyond capacity. The three interact: cutting muda by removing slack raises muri, and levelling mura is what makes the reduction hold.
In practice
- A team that removes its buffer hits every target for a quarter and loses two people in the fourth.
- A clinic that smooths its appointment book treats the same number of patients with less overtime.