Ishikawa Diagram

Ishikawa Diagram

Ishikawa diagrams (also called fishbone diagrams, herringbone diagrams, cause-and-effect diagrams, or Fishikawa) are causal diagrams created by Kaoru Ishikawa (1968) that show the causes of a specific event. Common uses of the Ishikawa diagram are product design and quality defect prevention, to identify potential factors causing an overall effect. Each cause or reason for imperfection is a source of variation. Causes are usually grouped into major categories to identify these sources of variation. The categories typically include:

• People: Anyone involved with the process
• Methods: How the process is performed and the specific requirements for doing it, such as policies, procedures, rules, regulations and laws
• Machines: Any equipment, computers, tools etc. required to accomplish the job
• Materials: Raw materials, parts, pens, paper, etc. used to produce the final product
• Measurements: Data generated from the process that are used to evaluate its quality
• Environment: The conditions, such as location, time, temperature, and culture in which the process operates