A fishbone diagram, also known as an Ishikawa diagram or cause and effect diagram, is a tool used to identify the root causes of a problem. It is named after Japanese quality control expert Kaoru Ishikawa, who developed the concept in the 1960s.

Ishikawa diagrams (also called fishbone diagrams, herringbone diagrams, cause-and-effect diagrams) are causal diagrams created by Kaoru Ishikawa that show the potential causes of a specific event. [1] Common uses of the Ishikawa diagram are product design and quality defect prevention to identify potential factors causing an overall effect.