The fishbone diagram is a method of clarifying a problem. The technique best works with problems which start with terms like What, Why and How.
Once the problem is identified and placed at the head of the fish, the bones of the issue are defined using different categories. These are the parts of the problem which will be dealt with individually. Categories are decided by brainstorming the general issues of the problem. Typically they may include:
M's: Man, Machine, Method, Materials Maintenance and Mother Each (Environment)
P's: Price, Promotion, People, Processes, Place/Plant, Policies, Procedures and Product
S's: Surroundings, Suppliers, Systems, Skills, Service
This list is indicative and not exhaustive. The categories are used to stimulate brainstorming around the causes under each. At the end of the process the problem is more clearly defined.
