Before you prove a cause, you need all the candidates. The Fishbone DiagramA visual tool that organizes potential causes into standard categories (the Ms) branching off a spine toward the primary problem. Click term for full definition collects them, sorted into six categories, so nothing important gets overlooked. Watch the short video, then work with the toolkit PDF: it explains the method, shows a worked example and gives you a blank template to fill in.
Tool video
The short tool video will appear here.
Fishbone Diagram in short
- Walk the WallsA team activity that reviews the merged process map and data from the Measure phase to harvest potential causes at each "hot spot." Click term for full definition. Walk your map and data, stop at every hot spot and ask: why does this step perform poorly?
- Write the head. Your Y as a question, e.g. “Why does OTIF fall short of target?”
- Draw the bones. Use the six Ms, or rename them to fit your process.
- Add the causes. One precise cause per note, on the right bone. Ask “why?” to go one level deeper.
- Mark the suspects. Circle the causes the team and the data point to. They go into A3 and A4.
Key points
- Head = your Y as a question.
- Six Ms as bones, adapt them freely.
- Precise causes, one per note.
- Suspects go to A3 and A4 for proof.