Core Idea
Definition
A premortem is a prospective failure analysis that asks participants to imagine the project or decision has gone badly and then generate plausible causes.
In Plain English
Pretend the plan failed six months from now and ask what most likely went wrong.
Framework Structure
Components
Flow
Assume failure -> Generate reasons it failed -> Group the risks -> Add mitigations before committing
How to Apply
- 1.State the plan or decision being evaluated
- 2.Ask the group to imagine it failed badly in the future
- 3.Have participants independently list plausible causes before discussion
- 4.Group the risks into themes and identify which are preventable
- 5.Use the results to redesign, de-risk, or stage the plan
When to Use
- •Before launches, hires, partnerships, or major commitments
- •When optimism is high and blind spots are likely
- •When teams need permission to voice concerns safely
- •Before irreversible or high-cost choices
- •Any situation where avoiding preventable failure matters more than performative confidence
When NOT to Use
- •When the exercise becomes performative pessimism without mitigation
- •When the team is too fragile to separate critique of the plan from critique of people
- •When there is no willingness to act on the discovered risks
- •When a postmortem would be more appropriate because the event has already happened
Example
Problem
A company is about to launch a complex new onboarding system.
Application
- 1.Imagine that the launch has failed three months later
- 2.Ask the team to write down why adoption stalled or customers became frustrated
- 3.Collect themes like confusing setup, weak internal support, and missing analytics
- 4.Address the highest-leverage risks before launch
Conclusion
The launch improves because likely failure modes are surfaced while there is still time to change course.
Takeaway
A premortem is useful because it legitimizes foresight about failure before reality makes it expensive.
Common Mistakes
- •Generating vague worries instead of specific failure paths
- •Letting senior voices dominate the risk list
- •Treating all risks as equally important
- •Running the exercise and then ignoring the output
- •Using it to discourage action instead of improving action
How to Practice
silent first listing
Have people generate failure causes individually before discussion to reduce conformity pressure.
specific cause rule
Translate vague concerns like execution problems into concrete failure paths.
mitigation follow through
Assign owners and actions to the highest-risk items so the premortem changes the plan.
Related Cognitive Biases
optimism bias
Premortems counter the tendency to underweight what could go wrong.
groupthink
The exercise can surface doubts people would otherwise suppress in a consensus-seeking group.
planning fallacy
Premortems reveal delays, dependencies, and failure points that clean plans often omit.
Related Frameworks
Related Skills
Variants & Extensions
Typical Failure Modes
- •Vague fear listing
- •No mitigation follow-through
- •Hierarchy-distorted discussion
Further Reading
- Decisive by Chip Heath and Dan Heath
- Thinking in Bets by Annie Duke
- The Checklist Manifesto by Atul Gawande