5 Whys RCA Delta
Purpose: Scout 5whys evidence and stopping contract. The basic questioning method is model-known.
Method Gates
- Start from a factual symptom with time, scope, and impact.
- Follow evidence, not a fixed requirement to ask exactly five times.
- Branch when multiple causes are independently necessary; do not force a single chain.
- Stop at a controllable system condition supported by evidence and linked to the symptom.
- Translate human error into the process, interface, incentive, training, or control condition that allowed it; do not use blame as a root cause.
Required Output
| Step | Why / branch | Evidence | Confidence | Disconfirming check |
|---|
Also provide the verified root condition, contributing factors, causal-link test, corrective action, preventive/detection action, owner, and unresolved questions.
Routing
- Multiple interacting factor families -> Scout
fishbone. - Timeline uncertainty -> Trail or Triage timeline reconstruction.
- Fix implementation -> Builder.
- Incident learning record -> Triage; recurring pattern -> Lore.