Catalog
method#Reliability#Governance#Delivery

Postmortem

A formal review after an incident to determine root causes, document findings, and derive improvements.

A postmortem is a structured review after incidents or failed releases.
Established
Medium

Classification

  • Medium
  • Organizational
  • Organizational
  • Intermediate

Technical context

Observability tools (monitoring, tracing)Ticketing and task management systemsKnowledge base / Confluence

Principles & goals

No blame; focus on causes and systems.Short, precise timeline and verifiable facts.Concrete, traceable actions with owners.
Iterate
Enterprise, Domain, Team

Use cases & scenarios

Compromises

  • Repetition without implementing actions.
  • Blame and team demotivation.
  • Sensitive information is insufficiently protected.
  • Establish a blameless approach to encourage open communication.
  • Start with a short timeline, then deep-dive as needed.
  • Integrate results into existing processes and playbooks.

I/O & resources

  • System and application logs
  • Monitoring and tracing metrics
  • Incident timeline and involved people
  • Root cause analysis report
  • Action plan with owners and deadlines
  • Learnings for playbooks and processes

Description

A postmortem is a structured review after incidents or failed releases. It documents causes, impacts and actions, promotes a learning culture and helps prevent recurring issues. The goal is sustainable improvement of processes and system reliability.

✔

  • Improved system stability through targeted countermeasures.
  • Knowledge transfer and organizational learning.
  • Reduction of recurring incidents.

✖

  • Success depends on openness and company culture.
  • Time-consuming for complex or poorly documented systems.
  • Can remain superficial without clear follow-up processes.

  • Mean Time to Recovery (MTTR)

    Average time to restore a service after an incident.

  • Number of recurring incidents

    Counts incidents with the same root cause within a defined period.

  • Implementation rate of recommended actions

    Percentage of postmortem recommendations implemented on schedule.

Incident analysis: Auth service outage

Documented postmortem with timeline, RCA and three follow-up tasks to stabilize service.

Failed rollout rolled back

Postmortem revealed missing canary checks; deployment process adjusted.

Monthly risk review

Regular consolidation of postmortems to identify systemic weaknesses.

1

Define template and timeline; assign owners.

2

Collect data: logs, metrics and communication records.

3

Joint analysis session; derive causes and actions.

4

Put actions into backlogs and track progress.

⚠️ Technical debt & bottlenecks

  • Insufficient observability hampers RCA.
  • Outdated runbooks and missing playbooks.
  • Short-term hotfixes without sustainable solution.
Incomplete logsLack of cross-functional collaborationMissing follow-up tracking
  • Using postmortems as punitive tool in performance reviews.
  • Only symbolic postmortems without real data analysis.
  • Publishing internal details publicly without risk assessment.
  • Conducting too late leads to unreliable memories.
  • Lack of prioritization of derived actions.
  • Missing measurement of the effect of implemented actions.
Root cause analysisModeration and facilitationSystemic thinking
Detectability of failures and eventsTraceability of processes and decisionsAvailability of observability data
  • • Time pressure after critical incidents
  • • Privacy and compliance requirements
  • • Limited resources for deep analyses