Creating Effective Post-Mortems

Post-mortems are structured reviews conducted after an incident, outage, failure, or unexpected event. Their purpose is not to assign blame, but to understand what happened, why it happened, and how the organization can prevent similar issues in the future. A good post-mortem turns a negative event into a long-term learning opportunity.

Incidents of any type — operational delays, communication breakdowns, safety issues, compliance failures, customer-impacting events — reveal weaknesses in processes and assumptions. Post-mortems help teams:

• Identify real root causes instead of superficial triggers.
• Improve processes and reduce repeat incidents.
• Strengthen communication and coordination.
• Build a culture of transparency and continuous improvement.

A high-quality post-mortem follows several key principles:

• Blamelessness — Focus on systems, processes, and context, not individuals.
• Fact-Based Review — Avoid speculation; use logs, timelines, and verifiable data.
• Root Cause Exploration — Look for systemic factors rather than “human error.”
• Actionability — The goal is improvement; every finding should inform a change.
• Inclusiveness — Gather input from all teams affected, not just those directly involved.
• Timeliness — Conduct the review soon after the incident while details are fresh.

A clear structure makes the review easier to understand and act on. A comprehensive post-mortem typically contains:

A short, neutral overview. What happened? Who was affected? Why does this matter?

Describe the consequences in measurable terms:

• affected customers or teams
• delayed operations
• financial or reputational impact
• safety or compliance implications

List events in chronological order — discovery, escalation, actions taken, attempted fixes, recovery. Stick to objective facts.

Identify underlying causes, not just symptoms. Useful tools include:

• “5 Whys”
• fishbone diagrams
• fault tree analysis
• workflow mapping

Focus on systemic contributors such as unclear procedures, inadequate tooling, missing training, or handoff gaps.

Highlight key insights:

• What surprised the team?
• What was harder than expected?
• What worked well and should be repeated?
• What warning signs were missed?

This section captures knowledge for future teams.

These should be:

• specific ("Clarify escalation paths for regional teams"),
• owned (assigned to a responsible person or department),
• time-bound (include deadlines),
• reviewed later (to track completion and evaluate effectiveness).

Avoid open-ended statements like “improve communication.”

Even the best document needs a good discussion. To ensure a constructive meeting:

• Set expectations upfront: no blame, no shaming.
• Encourage quieter team members to contribute.
• Keep the discussion focused on facts and improvements.
• Ensure psychological safety — people must feel safe describing mistakes openly.
• Summarize actions clearly at the end.

Record the meeting or share minutes so insights aren't lost.

Some problems can undermine the whole process:

• Turning the review into a search for “who messed up.”
• Focusing only on technical fixes while ignoring workflow or communication issues.
• Writing vague or unmeasurable action items.
• Never checking whether action items were completed.
• Conducting post-mortems only for large incidents, missing opportunities to learn from small ones.

The strongest organizations treat post-mortems as a normal part of operations. To build that culture:

• Conduct them regularly, not just in crises.
• Make them visible to relevant teams.
• Celebrate improvements that came from past incidents.
• Use post-mortem findings to guide training, process updates, and leadership decisions.

A healthy post-mortem practice builds trust, resilience, and long-term operational excellence.

• Ops Runbooks
• Infrastructure as Code
• Hero Developer
• Hero Sysadmin
• Postmortem Culture in Practice: What Production Incidents Taught Us about Reliability in Insurance Tech (Lalith Sriram Datla, International Journal of Emerging Research in Engineering and Technology, Volume 3, Issue 3, 40-49, 2022)