What is an Ishikawa diagram?

The Ishikawa diagram is also known as a fishbone diagram or cause-and-effect diagram. It visually represents a problem-solving process in which the primary causes of a problem are sought. The resulting diagram is one of the so-called “seven quality tools”.

All causes of the problem should be identified and their dependencies shown. A tree structure (Fault Tree Analysis) or table structure ( Cause and Effect Matrix) is often used as a presentation method.