Practice : Blameless Postmortems

Purpose and Strategic Importance

Blameless Postmortems turn incidents into learning opportunities. They allow teams to investigate what happened, why it happened, and how to prevent it in the future—without focusing on individual fault.

This practice builds psychological safety, accelerates improvement, and helps shift from reactive to proactive system design. By focusing on system conditions, not scapegoats, teams grow resilience and trust across the organisation.

Description of the Practice

  • A blameless postmortem is a structured review held after a significant incident or near miss.
  • The aim is to understand causes, not assign fault. Human error is treated as a symptom, not a root cause.
  • Reviews are time-boxed, facilitated, and use a consistent template to capture facts, impact, causes, actions, and follow-up.
  • Insights are documented and shared to benefit other teams and drive systemic change.
  • Postmortems are used across engineering, operations, security, and beyond.

How to Practise It (Playbook)

1. Getting Started

  • Define a trigger policy (e.g. all Sev 1/2 incidents must have a postmortem within 72 hours).
  • Use a simple, repeatable template:
    • What happened?
    • Timeline of events
    • What went well?
    • Where were the gaps?
    • What are the action items?
  • Designate a facilitator and assign roles: incident lead, scribe, observers.

2. Scaling and Maturing

  • Track action item completion rates and learning reuse across teams.
  • Review incident patterns quarterly to inform systemic improvements.
  • Link postmortem learnings to architecture reviews, platform priorities, and team rituals.
  • Create a searchable repository of reports tagged by cause, service, severity, and lessons.

3. Team Behaviours to Encourage

  • Speak from facts, not opinions or blame.
  • Ask “what made this error possible?” instead of “who caused it?”
  • Celebrate transparency—learning from near-misses is just as valuable.
  • Include all impacted roles (e.g. engineers, SREs, product, ops) to build shared understanding.
  • Treat every postmortem as a learning event, not just a retrospective.

4. Watch Out For…

  • Reviews that feel like finger-pointing or performance reviews.
  • Skipping or delaying postmortems because of fear or time pressure.
  • Focusing only on symptoms (e.g. restart the service) without addressing systemic causes (e.g. no circuit breaker).
  • Treating postmortems as a checkbox without follow-through on actions.

5. Signals of Success

  • Postmortems are held consistently and shared widely.
  • Teams are comfortable being open and honest about what went wrong.
  • Action items are completed and reduce repeat issues.
  • Engineers feel safer reporting incidents and contributing to improvements.
  • Insights influence broader systems, platforms, and processes.