Also known as a Cause and Effect diagram, or Ishikawa diagram. The method was created by Kaoru Ishikawa in the 1960’s. He created it to help employees avoid solutions that merely address the symptoms of a much larger problem.
The defect or problem is shown as the fish’s head on the right side (typically). The major categories or causes of the problem or defect are the ribs off the fish’s backbone.
The most common categories are the 6 M’s:
- Manpower (People)
- Methods (Processes/Procedures)
- Materials (Supplies/Vendors)
- Machines (Equipment)
- Mother Nature (Environment)
Another concept is 4 P’s:
From each rib, additional levels or root causes of each category become branches from the bones.