What Does Finite Capacity Mean in EDGEBIC?

Finite capacity means the scheduler refuses to book more hours on a work center than that work center genuinely has, so the plan it produces is one the plant can actually execute. In EDGEBIC by User Solutions this is not a mode you switch on but the foundation of every schedule run: each routing step is placed into real shift hours on a real machine, and when Monday's eight hours are gone, the rest of the work flows into Tuesday rather than being stacked on top of a day that has already sold out.

This entry is part of the EDGEBIC glossary series; for the broader vocabulary of production planning, see the manufacturing glossary and the generic industry definition of finite capacity.

How Finite Capacity Works

The distinction only makes sense against its opposite. Classic material requirements planning works backward from a due date through lead time offsets and produces a list of what should start when. It never asks whether the machine that must do the work has an hour free. That is infinite capacity planning, and it is genuinely useful for answering "what materials do we need" while being close to useless for answering "when will this actually ship."

A finite engine inverts the question. It does not compute a start date from an offset; it goes shopping for hours. For each step, it walks forward from the earliest moment the step is allowed to begin and asks a specific question of each day in turn: after everything already committed here, how many hours are genuinely left on this work center today? A single routing step can opt out of that question through its finite capacity flag, which is on by default.

That number is not the shift length. It is assembled from several layers:

• The shift pattern for that weekday supplies the base working hours.
• Plant holidays, work-center holidays, and downtime remove hours, whole days or partial ones.
• The instance count multiplies capacity, because a work center holding three identical machines offers three times the hours of one.
• Efficiency and the utilization percentage scale it down, so a work center you only want loaded to eighty percent offers eight tenths of its nominal hours to the planner.
• A capacity override replaces the calculated figure outright for one work center on one date, which is how a planner zeroes out a machine for a Tuesday inventory count.
• Hours already claimed by other jobs are subtracted last.

Whatever survives all of that is what the step may take. If it needs more, it takes what is there, and the engine moves to the next day and asks again. A single step routinely spreads across several shifts and several days, which is exactly what happens on a real floor.

A Worked Example

Take the sample plant from the documentation. Day Shift runs 08:00 to 16:00, and CNC-Mill-1 holds one machine. JOB-2026-0102 needs two hours on Saw-1 and eight hours on the mill, starting Monday July 20.

The saw work runs Monday 08:00 to 10:00. The mill work then wants eight hours starting at 10:00. Monday only has six hours left after 10:00, so six hours land Monday 10:00 to 16:00 and the remaining two hours flow into Tuesday 08:00 to 10:00. Item Start comes back as Tuesday July 21 at 10:00.

Now add JOB-2026-0124 behind it. Its saw work takes Monday 10:00 to 16:00, right after the bracket's cut. Its two mill hours cannot begin Tuesday at 08:00, because the mill is still finishing the first job until 10:00. They land Tuesday 10:00 to 12:00.

Nothing here required a rule about queuing. The second job started later purely because the first job had already taken those specific hours, and a finite engine cannot hand the same hour to two jobs. Swap the priorities and re-run, and the numbers move, because the order in which jobs go shopping decides who gets the good slots. This is why priority matters so much on a loaded plant, and it is the honest cost of a plan that adds up.

How EDGEBIC Uses Finite Capacity

Finite capacity is the reason several other behaviors in the product exist, and seeing the connections makes the whole model easier to hold:

• Days Late can turn red before the due date. Because the engine already knows the plan cannot fit the promise, it says so while there is still time to act rather than waiting for the calendar to catch up.
• The utilization percentage is a real planning knob. Setting a work center to eighty percent leaves genuine headroom for the unplanned, and the schedule respects it instead of quietly consuming it.
• The optimizer exists because greedy booking is fast, not perfect. Each job claims capacity completely before the next is planned, which always respects every constraint but can leave a better interleaving on the table. The optimizer searches for that better ordering against the same finite capacity model.
• Quoting runs the same engine. A quote simulation schedules a temporary job against your current real load, so the promised date already accounts for every hour the floor has committed elsewhere. Nothing is saved, and the live plan is untouched.
• Rescheduling preserves recorded work. Completed operations are frozen at the hours they really consumed, and only the remaining work goes back into the capacity search.

The practical discipline finite capacity demands is calendar hygiene. The engine plans against the shifts, holidays, downtime, and overrides as they stand at the moment you press the button. A calendar that still shows last year's holidays will produce a confident, precise, and wrong plan. The scheduling engine guide walks the full placement sequence, and finite versus infinite capacity scheduling sets out the trade-off in more depth. For the vocabulary of what the engine is actually doing while it searches, see available capacity in scheduling and the schedule-at-utilization setting.