A fishbone or Ishikawa diagram is a visual way to look at cause and effect. It is a structured approach to brainstorming, where the user goes through the different elements that may isolated potential root causes. These elements include Materials, Methods, Machines, Measurement, Mother Nature and Man. The problem or effect is displayed at the head or mouth of the fish. When the root cause is isolated, the user can use Five Why analysis to access the impact of the potential root causes.

Materials: Raw materials, components and consumables

Methods: A production process and its service delivery processes.

Machines: Systems, tools, facilities and equipment used for production.

Measurement: Manual or automatic inspections and physical measurements (distance, volume, temperature, pressure, etc.)

Mother Nature: Environmental factors that are unpredictable and uncontrollable.

Man: The labor of people engaged in the design and delivery of a product.