Cause-and-Effect Diagram

Posted on July 6, 2009 by



Cookies - please don't burn them!

The Cause-and-Effect Diagram is a method to uncover potential root causes of a given problem. They are also called Ishikawa Diagrams and Fishbone Diagrams, and were developed by Kaoru Ishikawa. It is listed as a tool and technique of the fourth edition PMBOK®’s Perform Quality Control process. Large arrows represent categories of reasons for the cause of the effect. The classic categories were the six “M’s” – Machine, Method, Maintenance, Materials, Man and Mother Nature. However, the categories can be adopted to fit the current problem. To the left is an example of a cause-and-effect diagram for Anna, who has burned batches of cookies lately. Notice that a smaller arrow provides a cause for the larger arrow to which it is pointing.