A cause and effect diagram, also known as an Ishikawa or "fishbone" diagram, is a graphic tool used to explore and display the possible causes of a certain effect. Use the classic fishbone diagram when causes group naturally under the categories of Materials, Methods, Equipment, Environment, and People. Use a process-type cause and effect diagram to show causes of problems at each step in the process.

A cause and effect diagram has a variety of benefits:

• It helps teams understand that there are many causes that contribute to an effect.
• It graphically displays the relationship of the causes to the effect and to each other.
• It helps to identify areas for improvement.

Used in IHI’s "Methods and Tools for Breakthrough Improvement" course, the cause and effect diagram has helped hundreds of health care organizations.

Download the tool for complete instructions.