Quick answer: A failed launch is the most valuable postmortem you'll run. Capture the timeline, the missed signals, and the system fixes before the team disperses to the next project.
Postmortems for failed launches build the next launch. Skip them and you'll repeat them.
Within 2 weeks
Schedule the postmortem 1-2 weeks after launch. Long enough to recover; short enough to remember.
Timeline before analysis
First 30 minutes of the meeting: just facts, in order. No interpretation. Then analysis with the timeline in hand.
Three categories of fix
Code fixes, process fixes, communication fixes. Each gets a tracked ticket and an owner. Without ownership, postmortems are theater.
Share with the org
Publish the postmortem. Not the names; the lessons. Other teams shouldn't have to repeat the discovery.
“Failed launches teach. The teaching is wasted if you don't capture it.”
Make 'no blame' a meeting ground rule, repeated at the start. Engineers will name themselves; the rule prevents others from naming them.