TB: Pre-mortem

Before a project begins, imagine it is a year later and the project has failed catastrophically. Then work backwards: what went wrong? The pre-mortem surfaces failure modes before they occur by granting explicit permission to voice doubt — countering the optimism and social pressure that suppress dissent during planning.

Planning is dominated by optimism bias and groupthink. The people most likely to know what can go wrong are often the least likely to say so in a culture of enthusiasm. The pre-mortem is a structured override: by declaring failure as a given, it removes the social cost of pessimism. It is inversion applied to project planning. Gary Klein (who named the technique) found it substantially improves a team's ability to identify threats before they materialize.

• Seeking Wisdom (Bevelin): pre-mortem as the inversion technique applied to planning; Bevelin pairs it with the checklist approach — enumerate what can go wrong before committing
• Poor Charlie's Almanack (Munger): Munger's "invert, always invert" — the pre-mortem is the operational form of this maxim in a team context

• Inversion — the pre-mortem is inversion applied to planning
• Second-Order Thinking — what happens after each failure mode? traces the cascade
• Sunk Cost Fallacy — pre-mortem prevents commitment that makes sunk-cost thinking inevitable