Cause-and-Effect Diagram

It helps teams uncover potential root causes by providing structure to cause identification effort. It is also called as fishbone or Ishikawa diagram. It helps in ensuring new ideas being generated during brainstorming by not overlooking any major possible cause.

It should be used for cause identification after clearly defining the problem. It is also useful as a cause—prevention tool by brainstorming ways to maintain or prevent future problems.

Developing Cause and Effect Diagram – It involves the following steps

• Name the problem or effect of interest. Be as specific as possible.
• Write the problem at the head of a fishbone “skeleton”
• Decide the major categories for causes and create the basic diagram on a flip chart or whiteboard.
• Typical categories include the manpower, machines, materials, methods, measurements and environment
• Brainstorm for more detailed causes and create the diagram either by working through each category or open brainstorming for any new input.
• Write suggestions onto self-stick notes and arrange in the fishbone format, placing each idea under the appropriate categories.
• Review the diagram for completeness.
• Eliminate causes that do not apply
• Brainstorm for more ideas in categories that contain fewer items
• Discuss the final diagram. Identify causes which are most critical for follow-up investigation.