PreMortem Exercise

The PreMortem Exercise is a technique for discovering critical flaws in a plan, by pretending that a plan failed and then trying to perform a list the reasons why it could have failed, then performing a post-mortem analysis on those theoretical failure causes. It was developed as part of the Decision Making Games for the U.S. Marine Corps by Gary Klein and colleagues.

Facilitating a PreMortem Exercise

A PreMortem exercise is a group activity, for stakeholders and delivery team members to jointly evaluate a proposed plan. In Linking Expertise and Naturalistic Decision Making, the authors suggest to ask the group to consider that, “by looking into a crystal ball it is determined that the plan failed”. Individual group members then need to spend a a bit of time independently writing down the potential reasons why the plan failed. The facilitator should then combine the potential reasons and lead a discussion until to clearly identify all the concerns.

How a PreMortem can help product development

By imagining that a plan has already failed, participants step outside their usual perspective and think more critically about potential weaknesses. This shift in framing helps uncover flaws that might otherwise be overlooked during optimistic planning. The exercise also creates a safe environment for raising concerns, since participants are explaining a hypothetical failure rather than criticising a proposed approach. Addressing the identified concerns typically leads to a stronger plan.

Learn more about the PreMortem Exercise