Overview

Based on "The Field Guide to Understanding Human Error" by Sidney Dekker and the Google SRE Book. Dekker's fundamental insight: human error is never the cause of an incident - it is a symptom of a system that put people in a position where mistakes were likely. A blameless postmortem asks not "who made the mistake?" but "what conditions made this mistake likely, and how do we change those conditions?"

Google SRE's postmortem culture: incidents are opportunities to improve systems, not to assign blame. Engineers who feel safe reporting mistakes surface problems before they become incidents.

Workflow

Step 1: Schedule within 48 hours (SEV1) or 1 week (SEV2)

Postmortems decay in value quickly. Memories fade, context is lost. Set the meeting within 48 hours of a SEV1 resolution.

Attendees: IC, Operations Lead, on-call engineer(s), and anyone who can contribute to understanding what happened. No executives in the room - their presence changes behavior.

Step 2: Build the timeline

Reconstruct what happened in chronological order. Be precise about times.