What it is for:A premortem is a short team exercise run before a plan starts. You leave with a ranked list of the most likely and damaging causes of failure, an early signal for each, and a named owner for every preventive action.
Who it helps:Project teams and sponsors about to commit to a plan, launch or purchase, especially when confidence is high and nobody has raised a concern.
When to use it
Just before you commit to a plan, a launch date, a pilot or a large purchase.
When the team seems very confident and nobody has raised a serious concern.
When a plan depends on other departments, suppliers or public behaviour you do not control.
How to use it
Brief the plan in three minutes so everyone shares one picture.
Say: it is a year from now and the plan has failed publicly.
Everyone writes causes alone, then shares them one at a time in rounds.
Pick the four to six risks that are both likely and damaging, and add an early signal to each.
Agree one preventive action and one owner per risk, without blaming anyone.
Tip:Ask the most senior person to write their notes and share last, so they do not set the tone.
Credits and sources:Original Tiremesù worksheet and wording. Method credit: Gary Klein. Further reading: Atlassian Team Playbook https://www.atlassian.com/team-playbook/plays/pre-mortem
Full guide and film:https://www.tiremesu.com/guides/premortem
