Four Ms
Problem Solving
Four Ms (4M)
Man, Machine, Material, Method
Common cause categories (Manpower, Machine, Material and Method) used to structure analysis of process problems.
Examples
- 01To explain a sudden rise in scratches, the team structures possible causes with the Four Ms: a new operator, a worn roller, a softer material batch and a changed handling method.
- 02Evidence for each of the Four Ms is collected and documented before the team agrees on the most likely cause.
- 03A follow-up check shows that replacing the roller, the Machine item of the Four Ms, removed the scratches without changes to the other three.