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Diffstat (limited to 'five-whys')
| -rw-r--r-- | five-whys/SKILL.md | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/five-whys/SKILL.md b/five-whys/SKILL.md index 7d7080d..e645f82 100644 --- a/five-whys/SKILL.md +++ b/five-whys/SKILL.md @@ -37,13 +37,20 @@ Good: "The 2026-04-17 release was rolled back at 14:02 after the cart-checkout e Bad: "Our releases are flaky." -### 2. Ask Why — One Answer +### 2. Ask Why — One Answer, With Evidence and a Counterfactual Not three possible answers. One best-supported answer, based on evidence you can point to. If the question genuinely has multiple independent causes, you'll branch in step 4. +Each link in the chain owes two things, not just an answer: + +- **Evidence** — what you can point to that supports this cause (a log line, a commit, a metric, a config value). "It seems like" without evidence is a guess, and a guessed link derails every why below it. +- **Counterfactual check** — if this cause were removed, would the symptom above it plausibly not have happened? If removing the cause leaves the symptom standing, you've named a coincidence, not a cause. This is the main guard against monocausal storytelling — a tidy chain that reads well but wouldn't actually have prevented the failure. + ``` Why did the release roll back? → The cart-checkout endpoint returned 500 on ~8% of traffic. + evidence: rollback log 14:02; APM 500-rate panel; error tracker grouped on CartController#checkout + counterfactual: no 500 spike → no rollback trigger fires → release stays up. Holds. ``` ### 3. Take the Answer as the New Question |