OPS.8.2:10 - Architectural Rationale

Protective capacity is useful through the work it can perform when needed. Its availability depends on capability, timing, location, access and state. The same idle machine or person can therefore be available for one protected service and unavailable for another.

The auxiliary unit, its interruption and the restoration form one operating construction. Keeping them together prevents an attractive auxiliary result from hiding the work needed to resume service. Preserving the auxiliary state and restoring the protected state remain separate contributions.

The method uses ordinary scheduling and capacity comparisons for the return. Its particular contribution is selecting and operating auxiliary work around that return, including the effects that remain after interruption. The comparison retains both the encompassing service and the smaller actions through which availability is restored.