A schedule becomes binding whenever others rely on it: at internal approval, at contract award, when it is presented to stakeholders, and in external reviews such as an IPA review. Each time, decisions are made on the basis of a document that hardly anyone can check in full – it is too large for that. This applies to a shutdown schedule just as much as to the schedule of a capital project: the technique of a schedule is the same, regardless of what is planned in it.
This is exactly where the SMI comes in: in two to four days, it makes measurable what otherwise remains a matter of experience. The results help you identify weaknesses quickly and eliminate them – an objective basis for discussion, both in-house and with contractors and partners. Ideally, commission it eight to ten weeks before such a milestone.