What Is a Requirement Type in a Routing Step?

A requirement type sets how a routing step is measured and scheduled: in hours, in pieces, or in both. Hours means the step is sized and placed on the schedule by the time it needs. Pieces means it is sized by the number of output units it must produce. Both means the step carries a time limit and a piece limit at once, and whichever is reached first constrains the schedule. The requirement type tells the engine which unit truly drives how long the operation takes, so the step lands on the calendar against the limit that actually binds it.

This entry defines the requirement type and shows how it behaves inside EDGEBIC by User Solutions. For the wider index of planning terms, see the manufacturing glossary, and for the same idea at the resource level, read what is capacity type in a work center.

How it works

Every routing step demands some amount of a resource, but not every step is honestly measured the same way. A machining operation is naturally measured in time: it needs so many hours regardless of the precise part count. A stamping operation is naturally measured in output: so many parts, at whatever rate the press runs. And some operations are genuinely limited by both. The requirement type is how a step declares which of these it is.

Under an Hours requirement, the step is scheduled by time. The engine reserves the hours it needs on a work center and places the block on the calendar accordingly.

Under a Pieces requirement, the step is scheduled by output. The engine converts the piece count into a duration using the work center's rate, the pieces per hour, so a piece-measured step still occupies a real block of finite capacity.

Under a Both requirement, two limits apply together. The step has an hours cap and a pieces cap, and the engine schedules against whichever it reaches first. A press rated at eight hours or a thousand pieces per shift will be piece-bound on a small job and hours-bound on a large one, and the binding limit is the one that shapes the schedule.

A concrete example

Consider three steps on the same job. A milling step is Hours: it needs four hours of machine time, and the engine reserves four hours no matter the exact part count. A stamping step is Pieces: it must produce five hundred parts, and on a press that runs a hundred parts an hour the engine turns that into five hours of capacity on the calendar.

A third step, on a press limited by both cycle time and part count, is Both. It is rated at eight hours or a thousand pieces per shift. For this job's eight hundred parts, the piece limit binds first, so the step finishes before the hours cap and is scheduled as piece-bound. Had the job called for fifteen hundred parts, the hours cap would bind first, and the step would be scheduled as hours-bound. In each case the engine placed the step against the limit that genuinely constrains it.

How EDGEBIC uses it

EDGEBIC reads the requirement type on each routing step to decide how to size and place the operation. Hours steps are scheduled by time. Pieces steps are converted to time through the work center rate so they still consume real finite capacity. Both steps carry two limits, and the engine schedules against whichever binds first, so a resource constrained on time and on output is never over-promised on either.

The requirement type on the step works hand in hand with the capacity type on the work center it runs at. A piece-measured step on a piece-capacity resource nets in pieces; an hours step on an hours resource nets in hours; and the Both settings let the binding limit decide. Because the engine always maps the requirement onto the finite hours a work center actually has, the placement respects real capacity whatever unit the step is measured in.

This keeps the schedule honest to how each operation truly behaves rather than forcing every step into a single unit. To see the resource-level counterpart, read what is capacity type in a work center. For how many machine instances a step may use, see what is applicable instances in a routing step. And for the routing these steps belong to, read what is a bill of routing.