thkt/use-context-root-cause-analysis

Root Cause Analysis - 5 Whys

Principle

Fix the root cause, not the symptom. Symptom fixes add complexity; root-cause fixes prevent recurrence.

5 Whys Process

Ask "why" five times, descending through abstraction levels.

| Step | Level | | ---- | ------------------------ | | 1 | Observable fact | | 2 | Implementation detail | | 3 | Design decision | | 4 | Architectural constraint | | 5 | Root cause |

Tips

| Tip | Description | | ---------------- | -------------------------------- | | Stay factual | Evidence, not assumptions | | Don't stop early | First "why" is rarely root cause | | Don't go deep | Stop when actionable | | Validate | "Because [5], therefore [4]..." | | Verify fix | "Will this prevent the problem?" | | Watch complexity signals | When intermittent / multiple independent changes overlap / behavior unexplained, enumerate ≥3 cause-layer candidates before converging |

Output Format

| Field | Description | | ---------- | ---------------------------------------- | | Symptom | User-facing failure | | Root cause | Why the failure occurred (5 Whys result) | | Pattern | Isolated / Recurring / Systematic |

Pattern Enum

| Value | Meaning | | ---------- | ------------------------------------------------- | | Isolated | Single location, no recurrence path | | Recurring | Similar code exists nearby, recurrence possible | | Systematic | Design-rooted, architecture-level recurrence risk |

Consumers (e.g., /fix Non-obvious flow) branch on the Pattern field to decide whether to apply defense-in-depth or escalate.

References

| Topic | File | | -------------------- | -------------------------------------------------- | | Worked examples | ${CLAUDE_SKILL_DIR}/references/five-whys.md | | Symptom → Root Cause | ${CLAUDE_SKILL_DIR}/references/symptom-patterns.md |