Blameless Postmortems
Blameless Postmortems are structured reviews conducted after an incident or project failure, focusing on identifying the root causes without assigning blame to individuals.
Goal
The primary goal is to learn from mistakes and system failures, improve processes and systems, and prevent future incidents without fostering fear or resentment among team members.
Context
Things go wrong, and often the underlying cause is not a single mistake but a combination of factors. It is easy to point the finger at someone but it is harder to understand the problems in the system that allowed the incident to happen. Blameless postmortems provide a safe space for teams to analyse incidents, identify root causes, and implement corrective actions without fear of retribution.
Root Cause Analysis Methods
| Method | Description | Benefits | Challenges |
|---|---|---|---|
| Five Whys | A technique that involves asking "Why?" five times to drill down into the root cause of a problem. | Simple and easy to use without specialised tools; promotes deeper thinking. | May oversimplify complex issues; relies heavily on the facilitator's expertise to guide the questioning effectively. |
| Fishbone Diagram (Ishikawa) | A visual tool that categorises potential causes of a problem into branches, helping to identify root causes. | Encourages systematic analysis; visually represents the relationship between effects and causes. | Can become unwieldy with complex issues; may require significant effort to categorise causes correctly. |
| Fault Tree Analysis (FTA) | A top-down, deductive failure analysis that uses a graphical diagram to model the pathways within a system that can lead to a failure. | Systematic and thorough; good for analysing complex systems. | Requires detailed system knowledge; can be time-consuming and complex to construct. |
| Failure Mode and Effects Analysis (FMEA) | A step-by-step approach for identifying all possible failures in a design, manufacturing or assembly process, or product or service. | Proactive risk management tool; helps prioritise issues based on severity, occurrence, and detectability. | Can be resource-intensive; effectiveness depends on the accuracy of the assumptions. |
| Pareto Analysis | Uses the Pareto Principle (80/20 rule) to identify the most significant causes contributing to a problem. | Helps focus efforts on the causes that will have the greatest impact if solved. | May overlook less obvious but still critical issues; assumes that the largest causes are the most important. |
| Root Cause Analysis Tree | A branching diagram used to map out the causes and sub-causes leading to an effect or problem. | Visual and structured approach to identifying root causes; can handle complex problems. | Building the tree can be time-consuming; requires a comprehensive understanding of all possible causes. |
Inputs
| Artifact | Description |
|---|---|
| Production Incident Report | A detailed account of the incident, including timelines and impact. |
| System Logs and Metrics | Data logs and performance metrics leading up to and during the incident. |
Outputs
| Artifact | Description | Benefits |
|---|---|---|
| Action Plan | Specific steps and timelines for implementing changes based on the postmortem findings. | Ensures continuous improvement and prevents recurrence. |
Anti-patterns
- Skipping sessions: Skipping postmortems for 'minor' incidents, missing learning opportunities.
- Allowing blame to seep in: Focusing on blaming individuals rather than understanding systemic issues.
- Going through the motions: Treating postmortems as a formality rather than an opportunity for genuine improvement.