Employee offboarding
Employee offboarding is the process of closing out someone's employment: revoking access, recovering equipment, settling obligations, and transferring their knowledge and responsibilities before their last day.
Most offboarding checklists are strong on the reversible parts and weak on the irreversible one. Laptops come back and accounts are disabled, both of which can be fixed later. The knowledge that walks out is the only item on the list that cannot be recovered afterwards.
Timing is the constraint. Notice periods are short, the person is disengaging, and the knowledge work competes with handover meetings and exit admin. Anything that depends on a departing person writing long documents in their final two weeks will not happen.
The practical version is narrow and evidence-led: find the small number of things only this person knows, ask about those and nothing else, and get each answer confirmed by a named colleague before the account is closed.