When to use it
Use it when a problem probably has several contributing causes and a team needs to explore them systematically.
How to apply it
- Write the problem at the head of the diagram.
- Draw main bones for cause categories, such as people, process, tools, materials, environment and measurement.
- Brainstorm possible causes under each category with the people closest to the work.
- Drill into the likeliest causes with follow-up questions or data.
- Select the causes with the strongest evidence and plan actions to address them.
Tip: Treat the finished diagram as a list of hypotheses to test, not a list of proven causes.