Voorraadbeheersing in de praktijk: over foute formules, niet-toegelaten oplossingen en wiskunde op drijfzand

We introduce the concept of material coordination and formulate a basic model for this. That basic model makes it possible to formulate the objective of material coordination, and to indicate the mathematical hurdles to be overcome. The essence of these hurdles are the stochastic processes we face. Even for simple stock control situations, exact methods are already numerically complex and therefore time-intensive. This still makes large-scale application difficult, even though computers are getting faster and faster. We discuss the typical "short-cuts" that are currently used within the so-called Enterprise Resource Planning (ERP) systems, which are used at almost every company. Here the wrong formulas and infeasible solutions pop up. These have implications for the daily work of planners, schedulers and managers. We argue that there are essentially solutions available, which have been over for quite some time, but are still not commonplace. Next, we discuss a number of laws that are of use when looking for new results. And finally, the mathematical challenges that are worth exploring further.