A full fishbone diagram can look like a completed investigation. In practice, it is often the beginning: a structured collection of explanations that still need evidence.
ASQ presents cause-and-effect diagrams as tools for identifying and organising possible causes of a problem. ASQ — fishbone.
Describe the effect narrowly
Define the observed issue and its boundary before brainstorming. A vague effect such as poor quality produces vague branches. A specific observation makes it easier to propose a test or find a relevant record.
Mark the status of each idea
Distinguish untested possibilities, unsupported ideas and causes supported by evidence. Do not allow a branch heading to become a conclusion simply because it appears plausible. Preserve contradictory evidence as part of the investigation.
For a sewing problem, several inputs may interact. The diagram helps organise that complexity, but the final explanation should show what was observed and why the chosen action follows from it.
Source reviewed 25 October 2026. Practical interpretation and original illustrations by PLUSHIP / Qunhe; examples are illustrative.
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