OPS.10:1 - Problem frame

Capacity is useful only relative to a service, resource capability, operating conditions and time window. Nominal resource hours, accessible hours, hours usable by the required skill or configuration, completed service visits and accepted operating results are different quantities.

Variability matters even when totals fit. Demand can arrive together, service can take longer, a provider can withdraw access, a qualified person can be absent, or failed work can return. The operation may have enough total hours and still miss a deadline because the needed hours occur at the wrong time or require incompatible resources.