Fishbone Diagram Template

What this template is for

A fishbone diagram — also called an Ishikawa diagram or cause-and-effect diagram — maps the potential causes of a problem along a spine that points to the effect. The six main bones represent categories from the 6M framework: People, Method, Machine, Material, Measurement, and Environment. Sub-branches on each bone capture specific causes within that category. The result is a structured visual that replaces unorganized brainstorming with a systematic search for root causes. This free template gives you a ready-to-edit fishbone built around a product quality problem — swap the labels to apply it to any issue in manufacturing, service, healthcare, software, or any other field.

When to use this template

• Investigate why a production defect rate increased and identify which of the six cause categories is the primary driver.
• Run a team brainstorm after an incident to surface all contributing factors before assigning corrective actions.
• Document the root causes of a service outage or bug for a post-mortem report.
• Prepare for a quality review by pre-filling the fishbone with known issues and gaps.
• Help students in a business or engineering course learn systematic problem analysis.
• Compare root cause hypotheses before committing resources to a fix — eliminate low-impact branches first.

How to use it

1. 1Write the problem or effect in the box at the right end of the spine (the fish head).
2. 2Label each of the six diagonal bones with a cause category — use 6M (People, Method, Machine, Material, Measurement, Environment) or 8P, or your own custom categories.
3. 3Brainstorm with your team: for each category, ask 'Why could this cause the problem?' and add causes to the relevant bone.
4. 4For major causes, drill deeper by asking 'Why?' again — add sub-causes as branches on the sub-bones.
5. 5Review all branches and identify the most likely root causes based on evidence, data, or team consensus.
6. 6Prioritize the top two or three root causes and assign owners to investigate and resolve each one.

Quick example