What Is a Stale Capacity Reservation in Scheduling?

A stale capacity reservation is a machine booking left behind by an earlier scheduling run for an operation that never started. It has to be released before a reschedule re-plans the job, or the engine sees the machine as busy with work that exists only on paper. EDGEBIC by User Solutions releases these bookings per operation, before any placement decision is made.

How it works

Before scheduling anything, the engine builds a capacity map: one slot for every combination of work center, shift, and date, each carrying the hours available and the hours already consumed. Existing schedules are loaded into that map so their bookings count against the capacity a new run may use.

That is exactly right for other jobs. It is wrong for the job being rescheduled, because the reschedule is about to place that work again. If its old bookings stay in the map, the job competes against its own previous plan, finds its preferred machines apparently full, and searches forward until it hits capacity nobody has claimed.

So the rebuild applies a filter. For a job that is not in the reschedule set, every booking is preserved and the capacity stays consumed. For a job that is in the set, only bookings with an actual start or actual end are kept. Everything else is dropped and its capacity returns to the pool.

The filter runs at operation level rather than job level, and that detail is what makes it work. A three-step job where step one has actuals and steps two and three do not keeps step one's reservation, because that machine genuinely was occupied, and releases the other two, because those hours were only planned. A job-level filter would preserve all three simply because one of them had run, and steps two and three would then be pushed out by their own phantom bookings.

Actuals are the discriminator throughout. A booking backed by a recorded start or end reflects something that happened and stays. A booking backed by nothing but a previous plan is an intention, and an intention that is about to be replaced should not be allowed to constrain its own replacement.

A concrete example

Think of a hotel that takes a provisional hold on a room when a booking is drafted. The hold blocks the room for anyone else, which is fine while the draft stands.

Now the guest calls to move the stay. The clerk goes to re-book and the system tells her the room is unavailable, because her own provisional hold from ten minutes ago is still on it. She books the guest three days later into a room that was free all along, and everyone is unhappy for no reason.

The correct sequence is to drop the hold first, then re-book. The room is free, the guest gets the night they asked for, and nothing was lost, because the hold was never a stay.

Change one thing: the guest already checked in for the first night. That night is not a hold, it is history. It stays occupied, nobody else gets it, and only the remaining nights are released and re-booked.

A reschedule is the same operation on machine hours. Release what was only ever provisional, keep what actually happened, then plan.

How EDGEBIC uses it

The release runs at the start of every scheduling run, before any job is placed, as part of the capacity map rebuild. Watching it happen on a real job, including the six-day symptom that shows up when reservations are not released, is walked through in how a reschedule frees stale capacity reservations.

The slot the bookings live in has its own glossary entry in shift resource allocation, and how much room a slot has left is covered in available capacity. Which jobs are in the reschedule set at all depends on the run's scheduling mode, so the mode you pick decides whose bookings are eligible for release.

The rule that decides which bookings survive is the same one that governs the rest of a reschedule: recorded work is untouchable. That is set out in actuals preservation on reschedule and in why actuals are immutable in EDGEBIC. For the wider vocabulary, see the manufacturing glossary, and to see a reschedule reclaim its own capacity, explore EDGEBIC.