Premortem

Premortem

Premortem is an optional plan-challenge strategy. It asks one fresh context to identify concrete ways the resolved bead or caller intent could fail before implementation. It is not part of the required RPI sequence and does not authorize readiness. Plan's shared challenge method owns optional exchange, independence and stopping rules; Premortem owns the three checks below. Neighbours: general advice is Review, acceptance of a finished change is Validate, and several independent views are Council.

Run the checks in this order; they outrank any single technical risk.

The first check: who verifies, and are they fresh?

Test the plan's evidence shape before any technical risk: for every unit of work, who verifies it, and is the verifying context distinct from the one that authored it? A plan whose closure step is "the implementer runs its own tests and closes" contains no independent judgment anywhere. Self-graded green is the classic false-done, and it ranks first because it silently converts every other failure into a shipped one.

The second check: which steps are one-way doors?

Walk the steps and mark each two-way (the plan can back out of it) or one-way (it cannot). For every one-way step name the exact undo cost, the point of no return, and who holds the handle when it is crossed: the caller, or an agent deciding inside a batch. A two-way failure costs a retry; a one-way failure costs the thing itself. Watch for nineteen reversible steps followed by an irreversible one, where the reflex trained by the first nineteen answers the twentieth.

The named failure mode is reversibility asserted, not traced: a rollback section that says "fully reversible" while one step revokes a credential, force-pushes or publishes. A material irreversible action outside existing caller authority is a finding; trace actual undo cost and authorization with Plan. Prior authorization remains valid: do not demand repeated approval at the crossing or call every uncertain detail irreversible. Stop condition: every step carries a mark, and every one-way mark carries its undo cost.