A pre-mortem is a decision exercise: assume the project or decision has already failed, then work backward to list why. The team imagines it is twelve months later and the launch has flopped, the deal has collapsed, or the bet has lost. Then each person writes or says the reasons it failed. The exercise surfaces risks and objections that normal planning suppresses. Optimism and group cohesion make it hard to say "this could go wrong" in a kickoff meeting. The pre-mortem gives permission: the failure is hypothetical, so naming causes is safe. The output is a list of failure modes to mitigate, monitor, or accept.
Gary Klein developed the method and showed that it increases the identification of risks compared to standard "what could go wrong?" discussion. The difference is psychological: when failure is assumed, the brain engages in a different search. Instead of defending the plan, people probe for weak points. The pre-mortem doesn't replace due diligence or red teams, but it is a fast, low-cost way to improve decisions before commitment. Use it for major bets: product launches, acquisitions, strategy pivots, key hires.
Section 2
How to See It
Pre-mortem thinking shows up when a team explicitly inverts success and asks "why did we fail?" The diagnostic: are people listing failure causes as if the failure has already happened? Look for sessions framed as "It's one year from now. We failed. What went wrong?" When post-mortems after a project are thorough but pre-mortems before the project are absent, the organisation is missing a cheap way to reduce failure. The pattern: assume failure, then explain it; use the explanations to harden the plan.
Business
You're seeing Pre-Mortem Analysis when a leadership team runs a session before a product launch: "Assume we've launched and it's a disaster. Revenue is zero, churn is 80%. Why?" Answers range from "we didn't fix the onboarding" to "sales oversold the roadmap" to "we had no retention strategy." The team then assigns owners to each risk or adds milestones to address them. The launch isn't guaranteed to succeed, but the plan has been stress-tested.
Technology
You're seeing Pre-Mortem Analysis when an engineering team does a "pre-mortem" before a major migration: "It's six months from now. The migration failed. What happened?" Responses include dependency hell, insufficient testing, and key person risk. The team adds rollback plans, staging phases, and documentation. The exercise converts vague anxiety into actionable risks.
Investing
You're seeing Pre-Mortem Analysis when an investor writes a "why I'm wrong" memo before leading a round. They assume the investment fails: the market was smaller than thought, the team didn't scale, competition won. The memo forces explicit consideration of the main failure modes and whether the thesis still holds. The same logic applies to founders before raising: "Assume we didn't get the round. Why?"
Markets
You're seeing Pre-Mortem Analysis when a regulator or policy team runs a "failure scenario" before a new rule or programme. "Assume this policy has failed. What went wrong?" The answers inform monitoring, sunset clauses, and design changes. The exercise reduces overconfidence in the initial design.
Section 3
How to Use It
Decision filter
"Before committing to a major decision or project, run a pre-mortem: assume it has already failed. List the reasons. Use the list to add mitigations, milestones, or exit criteria. If the failure modes are unacceptable and unaddressable, reconsider the decision."
As a founder
Run a pre-mortem before big bets: a pivot, a key hire, a major partnership, a fundraise. Gather the core team. Set the scene: "It's [time] from now. This [decision] has failed. Why?" Collect answers without debate. Then prioritise: which failure modes can we mitigate? Which do we accept? Which should make us delay or change the plan? The mistake is treating the pre-mortem as a one-off. Revisit when the plan changes or new information arrives. The second mistake is doing it only for projects and not for strategic decisions — hires and partnerships benefit too.
As an investor
Before leading a round or making a large commitment, write a "why this fails" memo. Assume the investment is a write-off. List the reasons: market, team, competition, execution, timing. Then ask: are these risks priced? Can we mitigate any? Does the upside still justify the bet? The pre-mortem doesn't replace diligence, but it sharpens the thesis and surfaces blind spots. Use it for portfolio companies before major strategy shifts as well — have the team run a pre-mortem on the new strategy.
As a decision-maker
When your team is about to commit to a plan, schedule a pre-mortem. Make the framing clear: we're not killing the plan; we're stress-testing it. Assume failure; list causes; assign mitigations or accept risks. The exercise works best when participation is broad — include people who might otherwise stay silent. After the pre-mortem, update the plan and, where possible, add leading indicators for the main failure modes. Re-run when assumptions change.
Common misapplication: Using the pre-mortem to kill every initiative. The goal is to improve the plan, not to create a culture of fear. If every pre-mortem leads to "we shouldn't do this," the exercise is being used to avoid risk rather than to manage it. The output should be a better plan and clearer risks, not paralysis.
Second misapplication: Doing it once and forgetting the list. The pre-mortem produces a list of failure modes. If no one owns mitigations and no one tracks them, the exercise was theatre. Assign owners. Add checkpoints. Revisit the list at milestones.
Grove was known for "only the paranoid survive" and for stress-testing strategies. He asked "what could kill us?" and "what would we do if our key assumption is wrong?" — a form of pre-mortem thinking. Before major moves, Intel would scenario-plan failure and adjust. The discipline was to assume the worst could happen and then build the plan and the organisation to respond.
Bezos has emphasised the value of "disagree and commit" and of writing six-page memos to force clarity. Amazon's culture of "working backwards" from the customer and from the press release is a kind of pre-mortem: assume the product exists and the press release is written; what would it say? What would have had to go right? The inverse — what would have to go wrong for this to fail? — is the same cognitive move. Bezos also advocated for "type 2" decisions to be reversible and for learning from failure; the pre-mortem is a way to learn before failing.
Section 6
Visual Explanation
Pre-Mortem Analysis: Assume the decision or project has already failed. List reasons. Use the list to add mitigations, owners, and checkpoints.
Section 7
Connected Models
Pre-mortem analysis sits with other risk and decision tools. The connections below either complement it (red team, scenario analysis), explain why it's needed (planning fallacy, confirmation bias), or extend the same logic (stress testing, unknown unknowns).
Reinforces
Red Team
A red team attacks the plan; a pre-mortem assumes failure and explains it. Both surface weaknesses that normal planning misses. Red teaming is often more resource-intensive and adversarial. The pre-mortem is a lightweight, internal version. Use the pre-mortem for routine stress-testing; escalate to red team when the stakes justify it.
Reinforces
Scenario Analysis
Scenario analysis explores multiple futures — best, base, worst. The pre-mortem focuses on the worst: assume failure and work backward. Both improve preparedness. Scenarios are often more structured and quantitative; the pre-mortem is qualitative and fast. They can be combined: run a pre-mortem for the worst-case scenario to list causes and mitigations.
Reinforces
Stress Testing
Stress testing asks "what if X goes wrong?" and measures impact. The pre-mortem asks "we failed; why?" and generates X. Both improve resilience. Stress tests are often financial or operational; the pre-mortem is strategic and behavioural. Use the pre-mortem to identify what to stress-test.
Leads-to
Planning Fallacy
The planning fallacy is the tendency to underestimate time, cost, and risk. The pre-mortem is a corrective: by assuming failure, we surface risks we would otherwise neglect. Run pre-mortems to counteract the planning fallacy on major projects.
Section 8
One Key Quote
"In a pre-mortem, the team imagines that the project has failed and then generates plausible reasons for the failure. This overcomes the tendency to be overconfident and helps the team identify risks that might otherwise be overlooked."
— Gary Klein, The Power of Intuition (2004)
The quote captures the purpose: overcome overconfidence and find risks we'd overlook. The hypothetical failure is the device that makes it safe and cognitively effective. The practitioner's job: run the exercise before commitment, record the causes, and convert them into mitigations and checkpoints. Don't let the list sit in a drawer.
Section 9
Analyst's Take
Faster Than Normal — Editorial View
Run it before commitment, not after. The value of the pre-mortem is before the decision is locked in. Once the team has publicly committed, the same exercise becomes harder — people defend the plan. Schedule the pre-mortem before the go/no-go or before the board presentation.
Make the output actionable. A list of "why we failed" is useless if no one owns mitigations. Assign each major failure mode to an owner. Add milestones or metrics that would signal the risk is materialising. Revisit at project checkpoints.
Use it for decisions, not just projects. Pre-mortems are common for product launches and implementations. They're underused for strategic decisions: key hires, partnerships, market entry, fundraise timing. The same logic applies. Assume the hire was wrong, the partnership failed, the market entry flopped. Why? Then address or accept the risks.
Don't let it become a ritual. If the pre-mortem is a checkbox and the list is never integrated into the plan, it's theatre. The test: does the plan change after the pre-mortem? Do we add exit criteria, contingencies, or monitoring? If not, run the exercise differently or skip it.
Section 10
Test Yourself
Is this mental model at work here?
Scenario 1
A leadership team runs a session before a product launch: 'Assume we've launched and it's a disaster. Why?' They list causes, then assign owners to mitigate each.
Scenario 2
After a project fails, the team holds a post-mortem to understand what went wrong.
Scenario 3
An investor writes a 'why I'm wrong' memo before leading a round, listing the main ways the investment could fail, then checks whether the thesis still holds.
Section 11
Summary & Further Reading
Summary: Pre-Mortem Analysis is an exercise in which the team assumes a project or decision has already failed and lists the reasons. The hypothetical failure creates psychological safety and a different cognitive search, surfacing risks that normal planning misses. Use it before major bets; assign owners to failure modes and add mitigations or checkpoints. Don't use it to kill every initiative — use it to harden the plan. Connected ideas include red team, scenario analysis, stress testing, and planning fallacy.
Klein introduces the pre-mortem and places it in the context of naturalistic decision-making. The book covers how experts use intuition and how to improve decisions under uncertainty.
Kahneman discusses the pre-mortem as a debiasing technique. He and Klein collaborated on refining the method. The book provides the broader framework on biases that the pre-mortem helps counteract.
Gawande on checklists as a way to reduce failure in complex tasks. The pre-mortem produces a list of risks; checklists are one way to ensure mitigations are actually executed. Complementary practices.
Tension
Confirmation Bias
Confirmation bias leads us to seek evidence that supports our plan. The pre-mortem creates a frame where we seek evidence of failure — temporarily inverting the bias. The tension: without discipline, the pre-mortem can be done superficially and confirmation bias wins. Make the exercise explicit and record the output.
Leads-to
Unknown Unknowns
Unknown unknowns are risks we don't know we don't know. The pre-mortem can't list them by definition, but it can surface "we don't know if X" — which moves some unknown unknowns toward known unknowns. It also improves the chance that someone in the room names a risk others hadn't considered. Use the pre-mortem to expand the set of known risks.
