thinking-five-whys-plus

1# Five Whys Plus
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3Build an evidence-linked causal chain from a known proximate fault to an actionable systemic root, then prescribe a countermeasure that would have blocked it.
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5## When to Use
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7- A fault is already localized to a component, path, or subsystem.
8- The proximate cause is known, but recurrence or systemic root is not.
9- Prior symptom-only fixes failed and the failure returned.
10- You need prevention that addresses why the proximate cause was possible.
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12## When NOT to Use
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14- Fault is not localized or multiple candidate causes remain — discriminate first.
15- Root is evidenced and actionable — fix it.
16- No evidence can answer the next "why" — gather evidence.
17- One-off error without a process, tooling, or design enabler.
18- Selective defect needing IS/IS-NOT analysis.
19- Forward failure forecasting before commitment.
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21## Procedure
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231. **State the localized problem.** Record the observable symptom, confirmed component/path, time window, scope, and impact. Stop if localization is missing.
242. **Chain why with evidence.** Make the prior answer the new effect; propose a cause; cite logs, code, config, metrics, or witnesses; name and rule out alternatives. Stop on speculation.
253. **Branch before descending.** Ask what else could produce the same effect; keep every evidenced independent pathway. Treat the retained branches as a causal set rather than forcing one root.
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