A logistics client added two night-shift roles and still could not run a full aisle when the only forklift assessor took leave. The headcount file was green. The capability map was a single name.
Headcount answers “how many paid bodies”. Capability maps answer “which tasks die if this person is away”. They are not personality grids. They are lists of licences, sign-off rights, system access, and customer relationships that cannot be covered by a willing colleague.
We ask three questions in Succession Load Mapping. Who is the only person who can close this task? How many nights a year is that person rostered off? What is the training lead time if they resign on a Monday? If the lead time is longer than the notice period, you do not have a succession plan. You have a hope.
Finance often prefers FTE because it is easy to sum. Easy sums are how night shifts quietly become unsafe. Put the capability map next to the demand clock before you approve a requisition that looks cheap.