Definition
A pre-mortem is a structured exercise run before a project or decision is executed, in which the team assumes the initiative has already failed and works backward to identify plausible causes. It is prospective failure analysis — the mirror image of a Post-Mortem.
Why It Matters
Teams naturally overestimate success and underweight risks when planning forward. A pre-mortem legitimizes pessimism at the right moment: before commitment, when mitigation is still cheap. It converts vague anxiety into actionable failure modes and turns Proactivity from a trait into a repeatable ritual.
Core Concepts
- Prospective hindsight: Gary Klein’s method — ask “It’s six months later and this failed badly. Why?” instead of “What might go wrong?”
- Failure-mode inventory: Surface reasons for failure, consolidate, rank by likelihood and severity, and assign mitigations.
- Psychological safety for dissent: The format makes skepticism the assignment, not disloyalty — useful when Camaraderie Is Dangerous would otherwise suppress warnings.
- Pair with inversion: Inversion asks how to lose in principle; a pre-mortem makes that concrete for a specific plan.
- Pair with second-order thinking: After listing failures, ask Second-Order Thinking to trace ripple effects each failure would trigger.
- Where it lives in the vault: Step 3 of Difficult Decision Protocol — the protocol owns the procedure; this note defines the tool.