Everything you always wanted to know about S. Ex
Different models have been proposed to tackle school timetabling problems . In this paper we will concentrate on some types of constraints; our aim will be to show how these requirements may be handled in a graph theoretical model and more precisely in an edge coloring model. We will deal with some constraints of non-compactness which are usually important in the problems of S.Ex (i.e. scheduling of exams). Also several requirements of compactness will be taken into account.