C.39.QR:5.2 - An aggregate estimate leaves operating coverage open

An internal support team asks for an operating arrangement that keeps two qualified responders available throughout 09:00–12:00. A staffing spreadsheet sums the available person-hours and compares them with the six person-hours required. It finds 6.5 available. The sum is correct for the declared intervals. It establishes an aggregate capacity condition; the receiving question also requires simultaneous coverage, the needed access and an authorized allocation of the people.

In this constructed case, A is available 09:00–12:00 with a fixed break at 10:00–10:30; B is available 09:00–11:00; C is available 10:00–12:00. All three have the required working capability, but C initially lacks access to the service system. The service manager has authority to allocate their stated time. Recover the required whole condition: at every point in the interval, at least two assigned, qualified and equipped responders must be available. Total hours alone leave the time overlap and access conditions unresolved.

Working backwards from that condition exposes the first unsupported connection: B and C must cover A’s break, and A and C must cover the final hour. The manager obtains C’s role-appropriate access from its responsible administrator and verifies that C can perform the required service operation. The manager then makes the allocation explicit: A+B from 09:00 to 10:00, B+C from 10:00 to 10:30, A+B from 10:30 to 11:00, and A+C from 11:00 to 12:00. C’s remaining half-hour is unallocated. Each interval has the required two contributors, with the fixed break, availability and access conditions respected.

The completed contribution is this jointly feasible arrangement and its provisioned access. The manager communicates the assignments, obtains the performers’ acknowledgement and hands the arrangement to the duty lead for the stated period. Within the case’s supplied facts, the answer to the original coverage question is supported. The spreadsheet remains a useful capacity calculation; the interval construction and completed provisioning supply the previously missing grounds. Actual service quality during operation requires its own observation.

Now suppose C’s access becomes unavailable from 11:00. The available person-hours and their arithmetic are unchanged, while the final interval has only one equipped responder. Return to that connection. If an already qualified D is available and provisioned for 11:00–12:00, the manager assigns D alongside A and confirms the changed handover. Earlier intervals remain valid. If no such contribution can be obtained, the duty lead receives a precise uncovered interval and the original commitment remains unresolved; changing that commitment requires its authorized recipient. This is a different continuation from recalculating the unchanged aggregate hours.