Blameless Postmortems

A postmortem is a written record of an incident: its impact, what was done, its root causes and contributing factors, and the follow-up that prevents recurrence. Its value is proportional to what people learn from it and what changes because of it.

When one is required

Agree triggers in advance. Typical:

• User-visible downtime or degradation beyond a threshold.
• Data loss of any kind.
• On-call intervention such as a rollback or traffic reroute.
• Resolution time above a threshold.
• Monitoring failure (humans found it, not alerts).
• A single incident consuming a large share of error budget (per sre-slos-and-error-budgets).
• Anyone may request one for any event.

Blamelessness

Assume everyone acted reasonably with the information and tools they had. Focus on what in the system allowed the failure, not who.