Fish Bone Diagram – A Tool For Root Cause Analysis
The categories are not pre-defined but common ones include:
- Name the effect; determine the specific problem to be analyzed. Draw the diagram with a process arrow to the effect and draw a box around it.
- Decide what the major categories of the causes are (i.e., people, machines, measurement, materials, methods, environment, policies, etc.).
- Label categories important to your situation. Make it work for you.
- Brainstorm all possible causes and label each cause under the appropriate category.
- Post the diagram where others can add causes to it (i.e., experts, affected people, process owners, etc..).
- Analyze causes and eliminate trivial and/or frivolous ideas.
- Rank causes and circle the most likely ones for further consideration and study.
- Investigate the circled causes. Use other techniques to gather data and prioritize findings.
- Cause and effect analysis identifies core problems.
- Whenever multiple possible explanations exist for a single issue, root cause analysis enables the team to better understand the issues and prioritize their improvement efforts.
- Generates a large quantity a variable ideas in a short space of time.