The Pre-Mortem: Why Imagining Failure Before It Happens Produces Better Decisions
A pre-mortem is a structured technique that generates anticipation of failure — and it consistently improves planning and decision quality.
What Is a Pre-Mortem?
A pre-mortem, developed by research psychologist Gary Klein, is the inverse of a post-mortem (after-action review). Before beginning a project or major decision, participants imagine that the future has arrived — and the project has completely failed. They then work backwards to generate all the reasons why failure occurred.
This technique leverages a cognitive process called "prospective hindsight" — imagining a future event as having already occurred. Research by Deborah Mitchell and colleagues found that prospective hindsight increases the ability to correctly identify reasons for an outcome by approximately 30% compared to conventional prospective analysis.
Why It Works
Several cognitive mechanisms contribute to the pre-mortem's effectiveness:
- Defeats optimism bias — humans systematically overestimate the probability of success and underestimate the time, cost, and difficulty of projects (planning fallacy). The pre-mortem bypasses this by assuming failure, which gives the brain "permission" to think about problems that optimism bias normally suppresses.
- Overcomes group dynamics — in team settings, dissent is often socially uncomfortable. The pre-mortem reframes expressing concerns as fulfilling the exercise rather than being negative or undermining confidence, dramatically increasing the candour of shared concerns.
- Activates different knowledge — thinking forward (what do we need to do?) and thinking backward from failure (how did this go wrong?) activates different memory and reasoning structures, retrieving concerns that prospective planning misses.
How to Run One
- Set the scenario — "Imagine it is [date 6/12/24 months from now]. This project has failed completely. Not just stumbled — it has failed in every important way."
- Generate causes independently — each participant writes down all the reasons for failure they can think of, independently and simultaneously (prevents anchoring to the first person's ideas)
- Share and compile — round-robin sharing; each person reads one reason until all are on the table
- Prioritise and plan — identify which failure modes are most likely and most consequential; convert these into proactive mitigation steps in the actual plan
Individual Use
For personal decisions (career changes, major purchases, relationship decisions), a solo pre-mortem takes 15–20 minutes. Write "It is [date]. [Decision] has gone badly. Why?" then generate as many causes as possible. The discomfort of this exercise is a feature — it is precisely the concerns that feel uncomfortable to acknowledge that planning most often glosses over.
