What is a cause and effect diagram?
The cause and effect diagram was invented by Kaoru Ishikawa, a management expert, to improve quality control in the workplace. As the following example shows, cause and effect diagrams can also convey causality in other contexts. Cause and effect diagrams are also called Fishbone diagrams, because they look like the skeleton of a fish. The largest bones attached to the fish’s spine represent major categories of causes. In the example, the categories are Angles/Jutes, Danes, Saxons, and Normans, ethnic groups who battled for control of England. The smaller bones feeding into the categories represent primary causes. In the example, a primary cause of the Battle of Hastings from the Saxons category is that, in 1051 AD, Edward the Confessor promised the throne to William I. You can also add secondary causes that feed into primary causes.
