OPS.13:4.3 - Test the proposed promise at the required level

Start with a transparent load and time-window bound. If known work already exceeds usable resources before the deadline, select another plan or resource decision before adding a sophisticated model. Where order matters, lay out a feasible sequence with the required resources available together.

Compare the normal case with adverse and changed-condition cases that can alter this service decision. Include relevant repeats, absence, arrival bursts, failed inputs or delayed acceptance. State how each case consumes resources and which result it supports. Reserve time protects a named scenario only while its location, capability and availability fit that scenario.

A finite set of cases establishes what those cases show. A time-plus-probability promise needs a defensible forecast for the eligible population under sufficiently matching conditions. Inspect model assumptions, data coverage, dependence and the consequence of errors. Obtain appropriate forecasting or statistical expertise when that claim exceeds the available method.

Preserve customer classes or conditions whose losses matter separately. A favorable overall service proportion can coexist with an unacceptable result for a protected class. The target and the permitted consequence come from the service decision; the forecast supplies evidence for that decision.