Post-Mortem

A Post-Mortem is a structured reflection conducted after a project, event, or initiative — especially one that failed or had issues. The goal is to analyze what went wrong (or right), understand why it happened, and extract lessons to prevent future mistakes or replicate success.

Unlike a Pre-Mortem, which imagines failure in advance, a Post-Mortem looks backward after the fact. It’s a critical learning tool in engineering, product management, medicine, military operations, and startups.

“Every failure carries a lesson. Post-mortems make sure you actually learn it.”

Practical Applications

  • Project reviews: After launching a product or campaign, run a post-mortem to document what worked, what didn’t, and what you’d change next time.
  • Engineering incidents: After outages or bugs, conduct blameless post-mortems to understand root causes and improve systems.
  • Personal growth: After a missed goal or failed experiment, reflect: “What did I expect to happen? What really happened? Why?”
  • Team improvement: Use post-mortems to create a culture of learning, not blame — turning mistakes into process improvements.

Examples

  • A software team documents a failed deploy, tracing the cause to unclear handoffs between dev and ops — they revise the release checklist.
  • A sales team reviews a missed quota, uncovering that a new messaging strategy underperformed in their core market.
  • After a personal project stalls, you realize the failure came from unclear scope and lack of external accountability.

Pitfalls to Avoid

  • Blame culture: If people feel attacked, they’ll hide problems. A useful post-mortem must be psychologically safe and blame-free.
  • Surface-level analysis: Don’t stop at symptoms — dig into root causes using tools like the “Five Whys.”
  • No follow-through: Insights are meaningless without clear action items and accountability.

#mental-model #learning #feedback #decision-making #process-improvement #retrospective

Links to this note

Five Whys

The Five Whys is a simple but powerful method for identifying the root cause of a problem by asking “Why?” five times (or more, if needed). Each

Pre-Mortem

A Pre-Mortem is a mental model and planning exercise where you imagine a future failure — then work backward to figure out what caused it. Instead

Root Cause Analysis

(RCA) is a problem-solving method focused on identifying the underlying reason a problem occurred — not just its symptoms