An effective hybrid algorithm for university course timetabling

The university course timetabling problem is an optimisation problem in which a set of events has to be scheduled in timeslots and located in suitable rooms. Recently, a set of benchmark instances was introduced and used for an ‘International Timetabling Competition’ to which 24 algorithms were submitted by various research groups active in the field of timetabling. We describe and analyse a hybrid metaheuristic algorithm which was developed under the very same rules and deadlines imposed by the competition and outperformed the official winner. It combines various construction heuristics, tabu search, variable neighbourhood descent and simulated annealing. Due to the complexity of developing hybrid metaheuristics, we strongly relied on an experimental methodology for configuring the algorithms as well as for choosing proper parameter settings. In particular, we used racing procedures that allow an automatic or semi-automatic configuration of algorithms with a good save in time. Our successful example shows that the systematic design of hybrid algorithms through an experimental methodology leads to high performing algorithms for hard combinatorial optimisation problems. The work was carried out while Marco Chiarandini was with the Intellectics Group, at the Computer Science Department of the Darmstadt University of Technology, Hochschulstraße 10, 64283 Darmstadt, Germany. M. Chiarandini ( ) Department of Mathematics and Computer Science, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark e-mail: [email protected] M. Birattari · K. Socha Université Libre de Bruxelles, IRIDIA, Av. Franklin D. Roosevelt 50, CP 194/6, 1050 Bruxelles, Belgium e-mail: {mbiro, ksocha}@ulb.ac.be O. Rossi-Doria Napier University, School of Computing, 10 Colinton Road, Edinburgh, EH10 5DT, Scotland e-mail: [email protected] 404 J Sched (2006) 9:403–432