In 30 seconds
- Ask what in the system allowed this, not who did it.
- People share mistakes honestly when they're not punished.
- Blameless postmortems are the main practice.
Why blame backfires
When people are punished for mistakes, they hide them. Hidden problems grow. Engineering organizations such as Etsy and Google popularized blameless postmortems to keep information flowing after incidents.
A blameless postmortem
- Build a timeline of what happened.
- Ask why each decision made sense at the time.
- Find system factors: tooling, process, missing information.
- Agree actions that make the system safer.
- Share the write-up widely.
Blameless isn't consequence-free
People remain accountable for learning and improving. Blameless means no punishment for honest mistakes made in good faith. It depends on psychological safety.
Myth vs reality
Myth · Blameless means no accountability.
Reality · Accountability shifts to learning and fixing.
Myth · Human error is the root cause.
Reality · Human error is a symptom of system conditions.
Myth · Blameless only applies to outages.
Reality · It applies to any failure or mistake.
FAQ
Who should attend a postmortem?
Those involved plus anyone who can help fix the system.
How soon after an incident?
Within days, while memories are fresh.
What if negligence was involved?
Rare cases are handled separately; don't let them define the norm.