Postmortem Writing

by wshobson46891e7e60daNo licenseListed Oct 8, 2026Updated Oct 8, 2026

Write effective blameless postmortems with root cause analysis, timelines, and action items. Use when conducting incident reviews, writing postmortem documents, or improving incident response processes.

Instructions onlyProductivity & Workflow DevOps & Cloud

AI-generated overview

Guides writing blameless postmortems with timelines, root cause analysis, and action items.

What it does: Provides a structured guide for writing blameless postmortems after incidents, covering blameless culture, postmortem triggers, and a suggested timeline. It includes templates such as a 5 Whys analysis and a quick postmortem for minor incidents, plus a facilitation guide for postmortem meetings and lists of anti-patterns and best practices. It produces postmortem documents, root cause analyses, and follow-up action items.
When to use it: Use when conducting post-incident reviews, writing postmortem documents, or facilitating blameless postmortem meetings. Also relevant for identifying root causes and contributing factors, creating actionable follow-up items, and building an organizational learning culture.
Requirements: No tools, packages, or credentials required; instructions only. It references a companion file, references/details.md, for full templates and worked examples.

Postmortem Writing

Comprehensive guide to writing effective, blameless postmortems that drive organizational learning and prevent incident recurrence.

When to Use This Skill

Conducting post-incident reviews
Writing postmortem documents
Facilitating blameless postmortem meetings
Identifying root causes and contributing factors
Creating actionable follow-up items
Building organizational learning culture

Core Concepts

1. Blameless Culture

Blame-Focused	Blameless
"Who caused this?"	"What conditions allowed this?"
"Someone made a mistake"	"The system allowed this mistake"
Punish individuals	Improve systems
Hide information	Share learnings
Fear of speaking up	Psychological safety

2. Postmortem Triggers

SEV1 or SEV2 incidents
Customer-facing outages > 15 minutes
Data loss or security incidents
Near-misses that could have been severe
Novel failure modes
Incidents requiring unusual intervention

Quick Start

Postmortem Timeline

Day 0: Incident occursDay 1-2: Draft postmortem documentDay 3-5: Postmortem meetingDay 5-7: Finalize document, create ticketsWeek 2+: Action item completionQuarterly: Review patterns across incidents

Day 0: Incident occursDay 1-2: Draft postmortem documentDay 3-5: Postmortem meetingDay 5-7: Finalize document, create ticketsWeek 2+: Action item completionQuarterly: Review patterns across incidents

Templates and detailed worked examples

Full template library and detailed worked examples live in references/details.md. Read that file when you need the concrete templates.

Template 2: 5 Whys Analysis

markdown

# 5 Whys Analysis: [Incident]
## Problem Statement
Payment service experienced 47-minute outage due to database connection exhaustion.
## Analysis
### Why #1: Why did the service fail?
**Answer**: Database connections were exhausted, causing all new requests to fail.
**Evidence**: Metrics showed connection count at 100/100 (max), with 500+ pending requests.
---
### Why #2: Why were database connections exhausted?
**Answer**: Each incoming request opened a new database connection instead of using the connection pool.
**Evidence**: Code diff shows direct `DriverManager.getConnection()` instead of pooled `DataSource`.
---
### Why #3: Why did the code bypass the connection pool?
**Answer**: A developer refactored the repository class and inadvertently changed the connection acquisition method.
**Evidence**: PR #1234 shows the change, made while fixing a different bug.
---
### Why #4: Why wasn't this caught in code review?
**Answer**: The reviewer focused on the functional change (the bug fix) and didn't notice the infrastructure change.
**Evidence**: Review comments only discuss business logic.
---
### Why #5: Why isn't there a safety net for this type of change?
**Answer**: We lack automated tests that verify connection pool behavior and lack documentation about our connection patterns.
**Evidence**: Test suite has no tests for connection handling; wiki has no article on database connections.
## Root Causes Identified
1. **Primary**: Missing automated tests for infrastructure behavior2. **Secondary**: Insufficient documentation of architectural patterns3. **Tertiary**: Code review checklist doesn't include infrastructure considerations
## Systemic Improvements
| Root Cause    | Improvement                       | Type       || ------------- | --------------------------------- | ---------- || Missing tests | Add infrastructure behavior tests | Prevention || Missing docs  | Document connection patterns      | Prevention || Review gaps   | Update review checklist           | Detection  || No canary     | Implement canary deployments      | Mitigation |

# 5 Whys Analysis: [Incident]
## Problem Statement
Payment service experienced 47-minute outage due to database connection exhaustion.
## Analysis
### Why #1: Why did the service fail?
**Answer**: Database connections were exhausted, causing all new requests to fail.
**Evidence**: Metrics showed connection count at 100/100 (max), with 500+ pending requests.
---
### Why #2: Why were database connections exhausted?
**Answer**: Each incoming request opened a new database connection instead of using the connection pool.
**Evidence**: Code diff shows direct `DriverManager.getConnection()` instead of pooled `DataSource`.
---
### Why #3: Why did the code bypass the connection pool?
**Answer**: A developer refactored the repository class and inadvertently changed the connection acquisition method.
**Evidence**: PR #1234 shows the change, made while fixing a different bug.
---
### Why #4: Why wasn't this caught in code review?
**Answer**: The reviewer focused on the functional change (the bug fix) and didn't notice the infrastructure change.
**Evidence**: Review comments only discuss business logic.
---
### Why #5: Why isn't there a safety net for this type of change?
**Answer**: We lack automated tests that verify connection pool behavior and lack documentation about our connection patterns.
**Evidence**: Test suite has no tests for connection handling; wiki has no article on database connections.
## Root Causes Identified
1. **Primary**: Missing automated tests for infrastructure behavior2. **Secondary**: Insufficient documentation of architectural patterns3. **Tertiary**: Code review checklist doesn't include infrastructure considerations
## Systemic Improvements
| Root Cause    | Improvement                       | Type       || ------------- | --------------------------------- | ---------- || Missing tests | Add infrastructure behavior tests | Prevention || Missing docs  | Document connection patterns      | Prevention || Review gaps   | Update review checklist           | Detection  || No canary     | Implement canary deployments      | Mitigation |

Template 3: Quick Postmortem (Minor Incidents)

markdown

# Quick Postmortem: [Brief Title]
**Date**: 2024-01-15 | **Duration**: 12 min | **Severity**: SEV3
## What Happened
API latency spiked to 5s due to cache miss storm after cache flush.
## Timeline
- 10:00 - Cache flush initiated for config update- 10:02 - Latency alerts fire- 10:05 - Identified as cache miss storm- 10:08 - Enabled cache warming- 10:12 - Latency normalized
## Root Cause
Full cache flush for minor config update caused thundering herd.
## Fix
- Immediate: Enabled cache warming- Long-term: Implement partial cache invalidation (ENG-999)
## Lessons
Don't full-flush cache in production; use targeted invalidation.

# Quick Postmortem: [Brief Title]
**Date**: 2024-01-15 | **Duration**: 12 min | **Severity**: SEV3
## What Happened
API latency spiked to 5s due to cache miss storm after cache flush.
## Timeline
- 10:00 - Cache flush initiated for config update- 10:02 - Latency alerts fire- 10:05 - Identified as cache miss storm- 10:08 - Enabled cache warming- 10:12 - Latency normalized
## Root Cause
Full cache flush for minor config update caused thundering herd.
## Fix
- Immediate: Enabled cache warming- Long-term: Implement partial cache invalidation (ENG-999)
## Lessons
Don't full-flush cache in production; use targeted invalidation.

Facilitation Guide

Running a Postmortem Meeting

markdown

## Meeting Structure (60 minutes)
### 1. Opening (5 min)
- Remind everyone of blameless culture- "We're here to learn, not to blame"- Review meeting norms
### 2. Timeline Review (15 min)
- Walk through events chronologically- Ask clarifying questions- Identify gaps in timeline
### 3. Analysis Discussion (20 min)
- What failed?- Why did it fail?- What conditions allowed this?- What would have prevented it?
### 4. Action Items (15 min)
- Brainstorm improvements- Prioritize by impact and effort- Assign owners and due dates
### 5. Closing (5 min)
- Summarize key learnings- Confirm action item owners- Schedule follow-up if needed
## Facilitation Tips
- Keep discussion on track- Redirect blame to systems- Encourage quiet participants- Document dissenting views- Time-box tangents

## Meeting Structure (60 minutes)
### 1. Opening (5 min)
- Remind everyone of blameless culture- "We're here to learn, not to blame"- Review meeting norms
### 2. Timeline Review (15 min)
- Walk through events chronologically- Ask clarifying questions- Identify gaps in timeline
### 3. Analysis Discussion (20 min)
- What failed?- Why did it fail?- What conditions allowed this?- What would have prevented it?
### 4. Action Items (15 min)
- Brainstorm improvements- Prioritize by impact and effort- Assign owners and due dates
### 5. Closing (5 min)
- Summarize key learnings- Confirm action item owners- Schedule follow-up if needed
## Facilitation Tips
- Keep discussion on track- Redirect blame to systems- Encourage quiet participants- Document dissenting views- Time-box tangents

Anti-Patterns to Avoid

Anti-Pattern	Problem	Better Approach
Blame game	Shuts down learning	Focus on systems
Shallow analysis	Doesn't prevent recurrence	Ask "why" 5 times
No action items	Waste of time	Always have concrete next steps
Unrealistic actions	Never completed	Scope to achievable tasks
No follow-up	Actions forgotten	Track in ticketing system

Best Practices

Do's

Start immediately - Memory fades fast
Be specific - Exact times, exact errors
Include graphs - Visual evidence
Assign owners - No orphan action items
Share widely - Organizational learning

Don'ts

Don't name and shame - Ever
Don't skip small incidents - They reveal patterns
Don't make it a blame doc - That kills learning
Don't create busywork - Actions should be meaningful
Don't skip follow-up - Verify actions completed

Source and attribution

Source:wshobson/agentsinplugins/incident-response/skills/postmortem-writingat commit46891e7

License: No license

Content belongs to its original authors. SourceWeft indexes it from a public repository.

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Postmortem Writing

Postmortem Writing

When to Use This Skill

Core Concepts

1. Blameless Culture

2. Postmortem Triggers

Quick Start

Postmortem Timeline

Templates and detailed worked examples

Template 2: 5 Whys Analysis

Template 3: Quick Postmortem (Minor Incidents)

Facilitation Guide

Running a Postmortem Meeting

Anti-Patterns to Avoid

Best Practices

Do's

Don'ts

Source and attribution

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