FPF.Preface:16.5.4.1 - Recover the receiving result

An engineer explains a reduction in response time from eight to five minutes, conditional on an operator being present. A colleague asks about night coverage, when no operator is present. Preserve the conditional explanation. The next useful contribution is a way to obtain the required night response, rather than another explanation of the same calculation.

For this worked example, define the operational requirement as follows: a qualified, authorized operator must start the applicable mitigation within five minutes of alarm detection during the seven nightly eight-hour windows. The requirement concerns the start of appropriate mitigation, not resolution of every incident. It applies to the declared incident class and at most one incident at a time. These added conditions make comparison possible; a real practitioner must obtain their actual counterparts from the service need.