Pre-mortem
Gary Klein's technique: imagine the plan has already failed, then work backward to explain why. Assuming failure makes it safe to name risks that optimism hides.
When to use
- Before a launch, migration, reorg, contract, hire, architecture change or any hard-to-reverse commitment.
- "What could go wrong?", "stress test this", "play out the failure".
- A plan everyone likes and nobody has attacked.
Skip: explaining a failure that already happened, or reviewing the logic of an argument rather than a plan.
Before you start
- State in one block: Plan (what, who, by when), Failure definition (what "failed badly" means, observable), Horizon, and Pass (Imagine, Causes, Rank, Mitigate, Decide).
- Gather first. Read the plan, timeline, dependencies, past incidents and similar launches before generating causes. Ask up to 3 questions only for what tools cannot answer.
- Light path. Small ask: 6 causes, top 3 ranked, one mitigation each.
Steps
1. Imagine
Write one sentence in the past tense: "It is [date]. The [plan] failed badly: [failure definition]."
2. Causes
List reasons it failed. Cover different angles so they do not cluster: people and skills, process and timeline, technology and dependencies, customers and market, money, external events. Add one inversion prompt: "What would guarantee failure?" and list what you would then have to avoid. Each cause is a specific story ("the vendor API changes its rate limit during launch week"), not a category ("vendor risk").
3. Rank
For each cause give a plain-language likelihood, impact if it happens, and an early warning sign. Keep the top 5-8.
| Cause | Likelihood | Impact | Early warning |
|---|
4. Mitigate
For each top cause choose one:
- Prevent: change the plan so it cannot happen.
- Detect: a metric or check that shows it early.
- Respond: a rehearsed fallback.
Add an owner (or "to be assigned").
5. Decide
- Plan changes to make now.
- Tripwires: conditions under which the plan is paused, changed or stopped.
- Go / no-go statement: go as is, go with changes, or hold until named risks are reduced.
Pitfalls
- Generic risks ("scope creep") with no story. Write what it looks like when it happens.
- Everything high likelihood and high impact. Force a ranking; a list where all items matter does not guide action.
- Mitigations nobody owns. Name an owner or mark it unassigned.
- Using it on something already failed. That is a postmortem; use a root-cause method.
- Treating the output as a promise that nothing else will go wrong. Revisit at each tripwire.
Worked example: references/example.md.
Checklist
- Plan, failure definition and horizon stated
- Failure written in the past tense
- Causes are specific stories across several angles, plus an inversion prompt
- Ranked with likelihood, impact and an early warning sign
- Mitigations are prevent, detect or respond, with owners
- Tripwires and a go / no-go statement