Simulation in production planning and control

Enterprise planning always means to plan and set up a logistical system taking into account every aspect related to the expected performance of the system to be built. Logistics "performance" is to be benchmarked utilizing the four basic key figures of logistics: work in process (WIP), cycle time, resource utilization, and keeping of due dates. The process of enterprise planning implies the design of a specific dynamic relationship among these key figures. Thus, the result of the planning process is a certain dynamic behaviour of the factory (or distribution hub, etc.). Once the logistical system is built and put into operation, the plant manager has to cope with this behaviour for it is more or less built into the structures of the system itself. Thus, the person who has to operate and control a system on a daily basis has only limited influence concerning the change of a system's characteristics. However, this person has every opportunity to run the system under various conditions in order to choose the "ideal point of operation", respectively. These two processes (designing a system's characteristics and running a system within these characteristics) seem entirely different. The point is that the model based approach can be used in order to support both these processes. Thus, the "planning department" as well as the "plant manager" can utilize the very same tool in order to efficiently support their specific decision making tasks. Recently, simulation models have been very successfully integrated into the production planning and control process of various enterprises