fishbone-diagram

Fishbone Diagram

Use this skill to run Fishbone Diagram as a practical consulting method, not as a generic framework explanation.

Method Notes

• Use categories such as people, process, systems, policy, environment, and measurement.
• Prioritize cause branches for evidence testing.

Required Inputs

Collect or infer these inputs before execution:

• problem statement
• observed symptoms
• process context
• candidate cause categories

If an input is missing, do not block automatically. Mark it as missing, state the assumption used, and add a validation action.

When Not To Use

Do not use for a single verified linear cause or treat category branches as proven causes. Fishbone analysis is for exploring multiple cause families that still require evidence.

Adjacent Methods

• five-whys-root-cause: follow one selected branch deeper.
• systems-thinking: use for feedback and behavior over time.
• constraint-analysis: use for a proven binding bottleneck.

Step-by-Step Execution

Step	Required input	How to execute	Output
Define effect	Problem statement, defect, service failure, or outcome gap.	Place the problem at the head of the fishbone.	Effect statement.
Choose categories	Domain context.	Select people, process, systems, policy, environment, measurement, or custom categories.	Cause categories.
Populate causes	Evidence, team input, process facts.	List possible causes under each category.	Fishbone cause map.
Mark evidence	Cause map and available data.	Label causes as evidenced, assumed, contradicted, or unknown.	Evidence-coded fishbone.
Prioritize tests	Evidence-coded fishbone.	Choose top cause branches and validation tests.	Root-cause test plan.

Output Template

### 1. Effect And Boundary
Observed effect:
Location / period:
Baseline:
In scope / out of scope:

### 2. Cause Map
| Category | Possible cause | Evidence status | Mechanism |
|---|---|---|---|
|  |  |  |  |

### 3. Priority Causes
| Cause | Impact if true | Testability | Confidence |
|---|---|---|---|
|  |  |  |  |

### 4. Test Plan
| Test | Owner | Timing | Confirming / disconfirming signal |
|---|---|---|---|
|  |  |  |  |

### Evidence And Next Decision
- Confirmed facts:
- Assumptions:
- Missing evidence:
- Next action, owner, and timing:
- Expected signal and decision threshold: