What Is Shift Time in Production Scheduling?

Shift time is the definition of a single day's working slot within a shift, a start time, an end time, and a break, that the scheduler decodes into the productive hours a work center has that day. It is the smallest building block of the capacity calendar, and every scheduled hour ultimately rests on it.

This entry defines shift time and shows how it reads inside EDGEBIC by User Solutions. For the wider index of terms, see the manufacturing glossary; for the limits that sit on top of it, see what is an overtime allowance in shift scheduling; and for the full calendar setup, see EDGEBIC shifts and calendars explained.

How it works

A shift is a named pattern of working hours, and it holds a shift time for each weekday it runs. Each shift time carries three values: a start time, an end time, and a break duration. The scheduler computes the day's productive hours as the span between start and end, minus the break.

The default slot runs 08:00 to 17:00 with a one-hour break, which yields eight productive hours. A weekday with no shift time is simply not a working day for that shift, which is how weekends and closures are expressed without any special flag.

Those productive hours are the base, not the final capacity. The engine takes the day's hours from the shift time, then multiplies by the work center's instance count and applies its utilization percentage to reach the schedulable capacity. Because everything downstream builds on the shift time, an error here propagates, which is why it is the first thing to get right.

A concrete example

Think of a shop's door sign: "Open 8 to 5, closed 12 to 1 for lunch." Anyone reading it knows the shop is available eight hours that day. A shift time is that sign for one weekday, and the scheduler reads it exactly that literally: open at start, closed at end, minus the posted break.

Take a day shift set 08:00 to 16:00 with a one-hour break. The gross span is eight hours, minus one hour of break, so the day contributes seven productive hours per instance. If the work center has two instances and a 100% utilization setting, that is fourteen schedulable hours for the day. Change the break to half an hour and the day gives 7.5 productive hours per instance instead. The scheduler never places work outside that window.

How EDGEBIC uses it

In EDGEBIC, shift times are configured on each shift as its daily working hours and decoded into per-day capacity when the scheduler runs. A weekday present in the shift's daily hours is open for that shift; a weekday absent is closed, which is how non-working days are modeled without a separate rule.

From those base hours the engine layers the rest of the capacity picture: the work center's instance count, its utilization percentage, and any downtime or holiday that removes time. So the shift time is where the calendar begins, and every richer capacity number, including the limits an overtime allowance describes, sits above it.

Getting shift times accurate keeps the whole plan honest, because the engine will only ever schedule into the hours a shift declares open. To see the overtime ceiling and flag that ride on top, read what is an overtime allowance in shift scheduling; to configure the full calendar, read EDGEBIC shifts and calendars explained. For the general concept, see shift scheduling.