Blameless postmortem
A blameless postmortem is an incident review structured to identify systemic causes — flawed processes, missing alerts, fragile dependencies — rather than individual fault. The blameless framing, popularised by Google SRE practice and John Allspaw's 2012 essay, is a structural commitment: nobody is identified as 'the cause' even when a specific action triggered the incident.
Blamelessness isn't moral; it's epistemic. The goal is to surface the real causal chain, which requires that the people involved feel safe describing what they did and why it seemed reasonable at the time. Blame culture destroys that safety: engineers stop volunteering information; postmortems become defensive theatre; the same incident recurs. Mature blameless postmortems still hold individuals to standards (the conduct itself can be addressed separately if needed) but the document focuses on the system. The five whys, contributing-factors analysis, and corrective-action ownership are the standard techniques; a good postmortem closes with concrete action items each owned by a named person with a date.
Related terms
- Postmortem
A postmortem is a structured retrospective on an incident or failure — capturing what happened, why, what was learned, and what will change.
- Premortem
A premortem is a planning exercise — formalised by Gary Klein in a 2007 Harvard Business Review article — where, before starting a project, the team imagines the project has failed and works backward to identify what could plausibly cause that failure.
- Five whys
Five Whys is a root-cause-analysis technique: ask 'why?' five times in a row (or until the answer becomes systemic rather than situational) to find the underlying cause of a problem.