Problem SolvingIntermediate

Ishikawa Diagram

Developed by Kaoru Ishikawa, this diagram visualises the causes of a problem in a structured fishbone shape. The problem (effect) sits at the right, with major cause categories branching off like fish bones. The most common categories are the 6Ms: Man, Machine, Method, Material, Measurement, Mother Nature (environment). It's a systematic root cause analysis tool that prevents teams from jumping to solutions too quickly.

Duration

30m–1h

Group size

2–15 people

Materials

whiteboard or flip chart, markers

Origin

Community

How to run it

1
Write the problem statement (effect) in a box on the right side of the board.
2
Draw a horizontal arrow pointing to the problem box — this is the 'spine'.
3
Draw 4–6 diagonal branches off the spine, one for each major cause category (use 6Ms, or customise for your context).
4
For each category, brainstorm contributing causes and add them as sub-branches.
5
Ask 'Why?' for each cause to find deeper root causes (combine with Five Whys).
6
Look for causes that appear in multiple categories — these are often the most significant.
7
Prioritise 1–3 root causes for action.

Tips

Use the 6Ms as starting categories but relabel them for your context (e.g.
for software: Code, Infrastructure, Process, People, Data, External).
Don't let the categories constrain — add a branch if something doesn't fit.

Variations

Combine with the Five Whys for deeper root cause analysis on individual branches. Run digitally using Miro or Lucidchart for distributed teams.

Where it fits

Root cause analysisQuality improvementIncident post-mortemsProcess problem solving

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Method descriptions on Workshop Weaver are original content written by our team, based on established facilitation practices.