Reformulation of Problems

Abstract

In this section we reconsider the task of modeling dealt with in previous chapters. As in linear programming, the basic task is that of defining appropriate variables and expressing the limitations or constraints on these variables in terms of linear relationships. However, straightforward modeling is not always adequate in integer and mixed integer programming. The practical user will soon find that much care needs to be expended in modeling, so that the final solution effort is acceptable. First we consider some common sense measures. Then we outline more complex steps, some of which are conceptual and may be useful at the very outset of creating a model. Finally we describe computational procedures that may be employed to transform a correctly, but poorly formulated model into a well formulated model. In other words, we will attempt to formulate models in such a way that they require less computational effort when solved with the standard procedures described in Chapters 5 and 6 of this part.