Monday, October 29, 2007


The Ishikawa diagram (also fishbone diagram or cause and effect diagram) is the brainchild of Kaoru Ishikawa, who pioneered quality management processes in the Kawasaki shipyards, and in the process became one of the founding fathers of modern management. It is simply a diagram that shows the causes of a certain event. It was first used in the 1960s, and is considered one of the seven basic tools of quality management, along with the histogram, Pareto chart, check sheet, control chart, flowchart, and scatter diagram. See Quality Management Glossary. It is known as a fishbone diagram because of its shape.

Causes in the diagram are often based around a certain category such as the 6 M's, 8 P's or 4 S's described below. Cause-and-effect diagrams can reveal key relationship among various variables and possible causes provide additional insight into process behaviour.