📝Postmortem

NEW

Also known as: Incident Postmortem, Blameless Postmortem, Post-Incident Review

A structured, blameless retrospective documenting an incident’s impact, causes, response, and follow-up actions to prevent recurrence.

DESCRIPTION

A postmortem is a written analysis of an incident that captures timeline, impact, root causes, contributing factors, detection gaps, and corrective actions. Blamelessness encourages psychological safety and comprehensive truth-finding. Postmortems improve resilience by driving preventive fixes, runbook updates, and SLO/SLI refinements. Good postmortems include clearly assigned owners and due dates for remediation and track learning across teams.

ALTERNATIVE DEFINITIONS

Google SRE Book

A postmortem is a written record of an incident, its impact, the actions taken to mitigate or resolve it, the root causes, and follow-up actions to prevent recurrence.

Emphasizes written record, root causes, and follow-up actions within a blameless culture.

Source

Atlassian

An incident postmortem is a process for learning from incidents by documenting what happened, why it happened, and how to prevent it from happening again.

Focuses on learning objectives and prevention in incident management context.

Source

RELATED TERMS

Incident Response Root Cause Analysis Problem Management Service Level Objective Service Level Indicator Error Budget Change Management Observability

COMPETING TERMS

After Action Review

KNOWLEDGE AREAS

Observability & Telemetry Software Engineering MLOps Testing & Validation

TARGET AUDIENCE

DevOps Engineer Software Developer IT Manager MLOps Engineer Data Engineer Chief Information Officer

EXTERNAL SOURCES

• Wikipedia - Postmortem documentation
• Google SRE Workbook - Practical guidance and templates for postmortems
• Microsoft Learn - Resiliency retrospectives guidance and checklists

TOP QUESTIONS

Why insist on blamelessness in a Postmortem?

Blameless culture encourages full disclosure and learning. It reduces defensiveness, helping teams identify systemic failures instead of individual fault.

Category: Relevancy

What should a Postmortem include?

Include summary, impact, timeline, root causes, contributing factors, detection and response analysis, and actionable follow-ups with owners and due dates.

Category: Requirements

How soon after an incident should a Postmortem be done?

Within a few business days while context is fresh. Schedule stakeholder reviews to validate facts and ensure follow-up commitments.

Category: Timing

What’s a common Postmortem mistake?

Focusing solely on immediate causes while ignoring systemic contributors like process gaps, documentation, and capacity limits.

Category: Mistakes

How do SLOs relate to Postmortems?

Breaches of SLOs often trigger postmortems. Findings inform new SLIs, thresholds, and error budget policies.

Category: Example

Should Postmortems be public within the company?

Yes, by default. Transparency spreads learning, but redact sensitive details when legal or privacy constraints apply.

Category: Opinion

Who owns Postmortem follow-ups?

Assign directly to responsible teams or individuals with deadlines, and track to closure in a centralized system.

Category: Management

How do Postmortems help audits?

They provide evidence of continuous improvement, incident documentation, and control enhancements, supporting compliance narratives.

Category: Compliance

What’s an effective Postmortem format?

Use a standardized template for consistency, with concise summaries and clearly labeled sections for impact, causes, and actions.

Category: BestPractices