Fishbone / Ishikawa Cause Analysis Tool
Define the problem clearly, explore potential causes using structured categories, assess each element using Red, Amber, Green or Not Applicable status, and generate a visual cause-and-effect diagram with a printable evidence report.
Problem definition
Describe the observed effect: state what is wrong, where it occurs, when it occurs and its extent. Avoid embedding an unverified cause in the statement.
Problem statement coach
0% completeCheck for symptoms versus causes: “The coating peeled because preparation was poor” assumes a cause. “Coating detached from 7 of 40 housings during adhesion testing after humidity exposure” describes the observable problem and leaves the cause open for investigation.
0
Elements assessed
0
Red / outside parameters
0
Amber / unknown
0
Green / within parameters
Potential cause categories
RAG guidance: Red means verified outside the required or expected parameter. Amber means unknown, insufficient evidence, marginal or not yet checked. Green means verified within parameter. Green does not prove that the element has no causal relationship; it records the current evidence.
Fishbone / Ishikawa Cause Analysis Report
Problem:
Generated:
Cause-and-effect diagram
Cause assessment table
| Category | Element / potential cause | RAG status | Evidence / rationale | Suspected cause |
|---|
Investigation and conclusion
Investigation priorities
Fishbone analysis identifies possibilities, not root cause. Verify suspected causes using evidence, comparison, testing, process data, controlled trials or reproduction of the failure mechanism.