Pre-Mortems: Imagining Failure Before It Happens

A pre-mortem is a planning exercise developed by psychologist Gary Klein. The exercise is simple: before starting a project, imagine that the project has already failed and describe in detail why. The team then uses this imagined failure to identify risks that ordinary planning misses.

The technique works because of a quirk of cognition: it is much easier to identify reasons why something could fail when you have committed, hypothetically, to the conclusion that it did fail. The frame change unlocks information that the optimistic planning frame suppresses.

How to run one

The exercise has a standard structure.

Step 1: Set the frame. Tell the team: “Imagine it is two years from now and the project has failed completely. Not partial success, not delayed success — total failure. The project did not deliver any of its intended outcomes.”

Step 2: Generate explanations. Ask each team member, individually, to write down the most likely reasons for the failure. Don’t discuss; just write. The individual writing prevents groupthink and surfaces concerns that wouldn’t emerge in group discussion.

Step 3: Aggregate and prioritize. Collect the answers and group them by theme. Identify the failure modes that came up most often. These are the risks that need active mitigation in the actual planning.

What it’s good for

Pre-mortems are particularly useful for projects with several characteristics.

Projects with significant unknowns. Routine projects with well-understood risks don’t benefit much from the exercise. Novel projects, where the failure modes are not obvious from past experience, benefit significantly.

Projects with strong organizational momentum. When a team is committed and excited about a project, the optimistic frame dominates. The pre-mortem provides a structured way to surface concerns that wouldn’t otherwise be voiced.

Projects with multiple stakeholders. The exercise gives each stakeholder a structured way to raise their specific concerns without having to position those concerns as opposition to the project.

Why it works

Pre-mortems work because they exploit a specific cognitive asymmetry. We are good at retrospectively explaining failures — once we know something went wrong, we can identify the reasons easily. We are much worse at prospectively predicting them — before something fails, the same causes are hard to see.

By asking the team to retrospectively explain a failure that hasn’t happened yet, the exercise puts them in the cognitive mode where failure explanation is easy. The explanations they generate are often accurate — the projects that actually fail tend to fail for the reasons identified in the pre-mortem.

Limitations

Pre-mortems are not magic. Several limitations are worth noting.

The exercise depends on the team’s ability to imagine relevant failure modes. If the team has limited experience in the domain, they may miss failure modes that an outside reviewer would catch. The exercise can be improved by including outside reviewers with relevant experience.

The exercise can produce a list of risks without producing the discipline to mitigate them. Many teams run pre-mortems, identify real risks, and then ignore them. The exercise is only useful if the identified risks change the actual planning.

The exercise can be co-opted by stakeholders who use it to express opposition rather than risks. A skilled facilitator distinguishes between “here’s a real risk that needs mitigation” and “here’s why I don’t want this project to happen.” Both are valid information, but they call for different responses.

Personal applications

Pre-mortems work for personal decisions, not just team projects. Before making a major personal decision — accepting a job, moving, starting a relationship, beginning a business — spend 20 minutes imagining the decision has failed completely and writing down why.

The exercise is uncomfortable. The imagined failure feels like inviting bad luck. But the discomfort is the point: the failure modes you identify in this state are the ones that should change your decision or your planning. The decisions you make after a pre-mortem tend to be more robust than the decisions you make from pure enthusiasm.