Dr. Kaoru Ishikawa, invented the fishbone diagram. Therefore, it can be also referred as Ishikawa diagram. Fishbone diagram is an analysis diagram which provides a systematic way of looking at effects and the causes that create or contribute to those effects. Because of the function of the fishbone diagram, it may be referred to as a cause-and-effect diagram. The design of the diagram looks much like the skeleton of a fish. Therefore, it is often referred to as the fishbone diagram.
Fishbone diagram helps in categorizing potential causes of problems or issues in an orderly way and in identifying root causes.