What Is Available Capacity in Production Scheduling?

Available capacity is the real working time a work center can offer on a given day after its shift hours, machine instances, and a planned utilization target are applied. It is the gap between what the calendar theoretically allows and what you can honestly promise, the way a restaurant with 20 tables plans for 16 covers to leave room for turnover. EDGEBIC loads jobs onto a work center only up to its available capacity, which is what makes the plan finite rather than wishful.

This entry is part of the EDGEBIC by User Solutions glossary series; for the broader vocabulary of planning, see the manufacturing glossary.

How Available Capacity Works

Raw calendar hours overstate what a work center can actually do. A machine might be staffed for two eight-hour shifts, but that does not mean sixteen productive hours are on offer. Some of that time goes to minor stoppages, changeovers, and the general slack of real operations, and if you plan as though every hour is available, the schedule slips the moment reality intrudes.

EDGEBIC turns calendar hours into available capacity through a single, well-defined calculation. It starts with the shift hours for the day, subtracts any downtime and holiday time, then multiplies by the number of machine instances and by the work center's utilization percentage, which sits at 100 percent in current versions. The result is the hours the scheduler is allowed to fill. Because this same calculation runs in one place, the number the dashboard shows and the number the scheduler uses can never disagree.

The deliberate cushion goes in earlier, in the shift definition itself or in a downtime event, because the utilization term is not editable on the work center screen. A work center that runs reliably can be described by its full clock; one prone to interruptions should be described by the hours it genuinely delivers. Shaping it there rather than behind a percentage means the plan carries a reason for every hour it holds back.

A Concrete Example

Take a welding cell with these settings for a normal Monday:

The available capacity is 7.0 hours times 2 instances times 1.00, which is 14.0 hours. The gross clock suggested more, because breaks and an hour of downtime already came off before the multiply, and jobs are loaded up to that 14.0 ceiling before the day is considered full.

Now suppose a partial retooling means this cell can run only 6 hours next Tuesday. You enter a daily capacity override of 6.0 for that work center, shift, and date. The override replaces the whole formula. EDGEBIC uses 6.0 exactly as entered and does not re-multiply it by instances, because an override is already the final figure for all machines on that day. Enter zero and the day is blacked out entirely; enter a negative number and it is rejected.

How EDGEBIC Uses It

Available capacity is the ceiling every finite-capacity decision respects. When the scheduling engine looks for a place to put an operation, it searches for a work center and shift that still has room under this number. Once a day is full, the engine moves the operation to the next available window rather than overloading the machine, which is the essence of finite scheduling.

The same figure drives the capacity views a planner reads. Because the dashboard and the engine both compute available capacity through the same chokepoint, the load bars you see and the hours the scheduler enforces are one number, not two estimates that drift apart. That consistency is what lets you trust a red overload warning: it reflects the exact hours the engine used.

Three levers change the result, and they are all planner-controlled. The number of instances reflects how many identical machines back the work center. The shift definition, together with any downtime, sets the honest length of the day. A daily capacity override handles the exceptions, replacing the formula for one specific day. Together they let you shape available capacity precisely without touching the scheduling logic itself. For the calendar side of the calculation, see the shifts and calendars guide, and for the exception mechanism see what a capacity override is.

Related Reading

Available capacity is what makes finite scheduling possible; contrast it with the naive approach in finite versus infinite capacity scheduling. To see how full work centers become constraints, read production bottleneck identification, and for the per-day exception field, what a capacity override is.