A Multicriteria Approach to Examination Timetabling

The main aim of this paper is to consider university examination timetabling problems as multicriteria decision problems. A new multicriteria approach to solving such problems is presented. A number of criteria will be defined with respect to a number of exam timetabling constraints. The criteria considered in this research concern room capacities, the proximity of the exams for the students, the order and locations of events, etc. Of course, the criteria have different levels of importance in different situations and for different institutions. The approach that we adopt is divided into two phases. The goal of the first phase is to find high-quality timetables with respect to each criterion separately. In the second phase, trade-offs between criteria values are carried out in order to find a compromised solution with respect to all the criteria simultaneously. This approach involves considering an ideal point in the criteria space which optimises all criteria at once. It is, of course, generally the case that a solution that corresponds to such a point does not exist. The heuristic search of the criteria space starts from the timetables obtained in the first phase with the aim of finding a solution that is as close as possible to this ideal point with respect to a certain defined distance measure. The developed methodology is validated, tested and discussed using real world examination data from various universities.