A Fishbone Diagram is a structured brainstorming tool designed to assist improvement teams in coming up with potential root causes for an undesirable effect. Its name derives from its resemblance to the bones of a fish. It is also known as a Cause and Effect Diagram or an Ishikawa Diagram after its creator.
Causes are often grouped into major categories, which are classically defined as the 6 Ms (or the 6 Ps):
- Man/Mind Power (People)
- Method (Process)
- Machines (Program)
- Materials (Product)
- Measurements (Policy)
- Milieu/Mother Nature (Place)
This tool is used in tandem with The 5 Whys.