Methods & toolsFishbone / Ishikawa Diagram

What is Fishbone diagram?

A fishbone diagram (Ishikawa diagram) is a cause-and-effect diagram that structures possible causes of a problem into categories — classically the 6 Ms: Man, Machine, Method, Material, Measurement and Milieu (environment).

The diagram is used in teams to brainstorm broadly before digging deep: first all plausible causes are gathered on the “bones”, then the most likely ones are prioritised for verification at the gemba — with data, not a show of hands.

Fishbone and 5 Whys complement each other: the fishbone opens up the breadth, 5 Whys drills into the depth on the selected causes.

Download the Fishbone template

Related concepts

5 Whys

5 Whys is a root-cause technique where you ask “why?” repeatedly — typically around five times — until you get from the symptom to the underlying cause that can be removed, so the problem doesn’t return.

Root cause analysis

Root cause analysis is a structured investigation that finds the underlying cause of a problem — the cause that, if removed, prevents recurrence. Symptom treatment removes the effect temporarily; root-cause treatment removes the problem permanently.

A3 problem solving

A3 is a structured problem-solving method where the entire analysis — background, current state, target, root cause, countermeasures and follow-up — is documented on a single A3 sheet. The format forces clarity: if the problem can’t be explained on one page, it isn’t understood.

From method to practice

A method only becomes real when someone uses it tomorrow. Our templates are print-ready and can be filled in directly — pick the one that fits what you are facing.

See all templates