Fishbone Diagram

A fishbone diagram, also called an Ishikawa diagram or cause-and-effect diagram, is a visual quality-management tool that organizes the possible causes of a problem into branches running off a central spine toward the stated effect, producing a shape that resembles a fish skeleton. The Japanese chemist and quality-control pioneer Kaoru Ishikawa devised the diagram in the 1960s while working to improve quality processes at Kawasaki Shipyards and later popularized it as one of what he called the seven basic tools of quality. The diagram is typically organized around standard cause categories such as people, methods, machines, materials, measurement and environment, and remains a widely taught root-cause analysis technique in industrial and manufacturing engineering.