Discrete event simulation of a theoretical manufacturing shop.
- Router
- A collection of manufacturing operations that is carried out during production of a good. Defines the order in which steps should happen, as well as the resources that accomplish those steps.
- Operation
- A single manufacturing step accomplished by a particular manufacturing resource.
- Workcenter
- An organizational unit or group of related manufacturing capabilities. Router operations are completed at (or by) workcenters.
Discrete event simulations must keep track of events as they happen, necessitating a way to quantify order. Time is a convenient and familiar metric for this. Here, however, time is also used to quantify how much work is to be done for a particular operation.
It is import to understand the distinction between how much work is accomplished in a workcenter and how much time passes on a wall clock, as they do not necessarily agree. It is possible for an hour to pass on the clock and have a workcenter accomplish more than an hours worth of work in that time.
For example, an Assembly operation (putting components together) may require 8 hours of touch labor to complete. If only one person is doing the work, then this 8 hours of work would take 8 hours on the clock. If two people are doing the work, they could presumably accomplish the task in half the time – 4 hours. Thus it is important to consider the rate at which work may be completed in a workcenter, quantified here by the ratio of work completion rate to the time elapsed on a clock.