Learn in the textbookBusiness Investigation Methods and QC-Style Problem Analysis
DefinitionA cause-and-effect diagram (特性要因図) arranges the factors that affect a given result (characteristic) in the shape of a fish skeleton, branching from broad categories down to specific factors.
ExplanationHere the characteristic is the outcome of quality or work, and a factor is anything that affects that outcome. Because factors are written out category by category, you do not stop at causes that happen to come to mind but list them more thoroughly, which makes the root cause easier to examine. Like the Pareto chart, it is one of the seven QC tools.
Memory hookFrom its shape it is also called a fishbone chart, and after its creator Kaoru Ishikawa, an Ishikawa diagram.