A date is an estimate with an unstated confidence level. What a factory can honestly promise is behaviour: a window, the conditions behind it, a call when they move, and a menu of responses.
Most delivery disputes are arguments about definitions. Split readiness from transit, measure at line level, and the conversation moves from an average to the three lines that were late.
Tooling is usually built before anyone asks who owns it. Ownership decides mobility, continuity and bargaining position years later, and it costs five written lines to settle.
Batch size is a decision about how expensive it will be to change course. Setup amortisation pulls one way, change cost and queue delay pull the other, and the textbook answer ignores both.
A line in its first shift is not the line at steady state. Fixtures are adjusted, programs proven and operators learning, which is why ramp-up needs its own plan and its own machine time.
Checklists prove that documents exist, not that practice matches them. A useful audit follows one part, watches one measurement, and asks specifically about ramp-up and tooling.
Recovery speed is decided long before a tool fails: by records, by pre-agreed substitution rules and by buffer placed where variability sits, not at the end of the plan.
Most factories sell time they do not control. A reservation names a window on a named operation, with a volume floor and an owner, which is what separates it from a priority agreement.
