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What is a Fishbone Diagram (aka Cause & Effect Diagram)?

A Fishbone Diagram is a structured brainstorming tool designed to assist improvement teams in listing potential root causes for an undesirable effect. Its name derives from its resemblance to the bones of a fish. It is also known as an Ishikawa Diagram after its creator.

Causes are often grouped into major categories, which are classically defined as the 6 Ms: Man/Mind Power (people), Methods (processes), Machines (technology), Materials (raw materials, information, consumables), Measurements (inspection), and Milieu/Mother Nature (environment). An additional 2 Ms are also sometimes used: Management/Money Power and Maintenance.

This tool is used in tandem with The 5 Whys.

5 Whys & Fishbone Diagram Training - GoLeanSixSigma.com

5 Whys & Fishbone Diagram Training
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For a better understanding of the Fishbone Diagram and an overview of Lean Six Sigma, check out our 5 Whys & Fishbone Diagram Training!


To learn how to use the Fishbone Diagram and how to apply Lean or Six Sigma, check out our free Lean Six Sigma Yellow Belt TrainingGreen Belt Training or Lean Training.

Elisabeth Swan

Elisabeth is a Managing Partner & Executive Advisor at GoLeanSixSigma.com. For over 25 years, she's helped leading organizations like Amazon, Charles Schwab and Starwood Hotels & Resorts build problem-solving muscles with Lean Six Sigma to achieve their goals.