No. 331 · Fixing problems · Biology
Post Mortem
After something goes wrong, look honestly at how it happened, so it never happens again.
In the Almanac
“The Rogers Commission”, 1986 · “GitLab”, 2017
Both stories in full, three ways to use it and where it misleads.
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What is Post Mortem?
A post mortem is a structured review after an event, especially a failure, to understand what happened and prevent it recurring. The Challenger inquiry found the causes were organisational as much as technical, and GitLab showed how a blameless review builds trust.
How do you use Post Mortem?
Use it after any setback that matters. Ask what you expected, what happened and what you will change. Review money mistakes without shame, and talk through arguments once emotions cool. Watch for hindsight bias, and never let it become a hunt for someone to blame.
When does Post Mortem matter?
Post Mortem is one of the 40 mental models for fixing problems, the situations where you ask: Why does this keep going wrong, and how do I fix it for good? Within that, it belongs to “Finding the real cause”, alongside Black Box, First Principles Thinking and Inversion.
What is an example of Post Mortem?
Two stories show it at work: The Rogers Commission (1986) and GitLab (2017). Both are told in full in The Mental Models Daily Almanac, which has two stories for each of its 365 models.
Which mental models are related to Post Mortem?
The 5 Whys, Hindsight Bias and Proximate vs Root Cause. Post Mortem itself comes from biology.