Abstract
Suppose we like to find non-overlapping periods for a set of events which may have multiple teachers assigned, is this easy or hard in terms of complexity? Or assume that only a single teacher is fixed per event, but we like to allocate rooms and periods simultaneously. What if a single teacher and a room is already given and we look for periods alone? And how do requests of teachers for specific rooms or additional student conflicts change the computational complexities of these questions from university course timetabling (UCT)? We provide a complete hard/easy-list of all UCT subproblems derived from a typical set of hard constraints. We obtain this list with a systematic study of the fine structure of UCT in terms of complexity w.r.t. the order in which rooms, periods and teachers are assigned to events. These kind of subproblems appear in practice when some entities in a timetable are fixed while the assignments of others are (re-)computed, and they also appear as necessary conditions for the existence of feasible timetables. Moreover, we identify which of the seemingly different subproblems are essentially the same computational tasks by reducing them to the same bipartite assignment problem, and we discuss some variations of constraints.


Similar content being viewed by others
References
Asratian, A., & de Werra, D. (2002). A generalized class-teacher model for some timetabling problems. European Journal of Operational Research, 143(3), 531–542.
Babaei, H., Karimpour, J., & Hadidi, A. (2015). A survey of approaches for university course timetabling problem. Computers and Industrial Engineering, 86, 43–59.
Chen, H. (2006). Logic column 17: A rendezvous of logic, complexity, and algebra. CoRR abs/cs/0611018, arXiv:cs/0611018
Cole, R., Ost, K., & Schirra, S. (2001). Edge-coloring bipartite multigraphs in O (E log D) time. Combinatorica, 21(1), 5–12.
Cooper, T. B., & Kingston, J. H. (1996). The complexity of timetable construction problems. In E. Burke & P. Ross (Eds.), Practice and theory of automated timetabling (pp. 281–295). Heidelberg: Springer.
Csima, J. (1965). Investigations on a time-table problem. Ph.D. thesis, School of Graduate Studies, University of Toronto.
de Werra, D. (1971). Construction of school timetables by flow methods. INFOR Journal, 9(1), 12–22.
de Werra, D. (2003). Constraints of availability in timetabling and scheduling. In E. Burke & P. De Causmaecker (Eds.), Practice and theory of automated timetabling IV (pp. 3–23). Heidelberg: Springer.
Dostert, M., Politz, A., & Schmitz, H. (2016). A complexity analysis and an algorithmic approach to student sectioning in existing timetables. Journal of Scheduling, 19(3), 285–293.
Even, S., Itai, A., & Shamir, A. (1975). On the complexity of time table and multi-commodity flow problems. In: Proceedings of the 16th Annual Symposium on Foundations of Computer Science, IEEE Computer Society, Washington, DC, SFCS ’75, pp. 184–193.
Ford, L. R., & Fulkerson, D. R. (1987). Maximal flow through a network (pp. 243–248). Boston: Birkhäuser Boston.
Garey, M. R., & Johnson, D. S. (1990). Computers and intractability: A guide to the theory of NP-completeness. New York: W. H. Freeman and Co.
Gaspero, L.D., Mccollum, B., & Schaerf, A. (2007). The second international timetabling competition (itc-2007): Curriculum-based course timetabling (track 3. Tech. rep.
Gotlieb, C.C. (1962). The Construction of class-teacher time-tables. In: IFIP Congress, pp 73–77
Holyer, I. (1981). The NP-completeness of edge-coloring. SIAM Journal on Computing, 10(4), 718–720.
Hopcroft, J. E., & Karp, R. M. (1973). An \(n^{5/2}\) algorithm for maximum matchings in bipartite graphs. SIAM Journal on Computing, 2(4), 225–231.
Karp, R. M. (1972). Reducibility among combinatorial problems (pp. 85–103). Boston: Springer.
Kingston, J. H. (2014). Timetable construction: the algorithms and complexity perspective. Annals of Operations Research, 218(1), 249–259.
Kostuch, P. (2005). The university course timetabling problem with a three-phase approach. In E. Burke & M. Trick (Eds.), Practice and theory of automated timetabling V (pp. 109–125). Heidelberg: Springer.
Kristiansen, S., & Stidsen, T. (2013). A comprehensive study of educational timetabling—a survey. Report 8.2013, Department of Management Engineering, Technical University of Denmark
Lach, G., & Lübbecke, M. E. (2012). Curriculum based course timetabling: new solutions to Udine benchmark instances. Annals of Operations Research, 194(1), 255–272.
Lewis, R., Paechter, B., & Mccollum, B. (2007). Post enrolment based course timetabling: A description of the problem model used for track two of the second international timetabling competition. Cardiff University, Cardiff Business School, Accounting and Finance Section, Cardiff Accounting and Finance Working Papers
Marx, D. (2005). NP-completeness of list coloring and precoloring extension on the edges of planar graphs. Journal of Graph Theory, 49(4), 313–324.
McCollum, B. (2006). University Timetabling: Bridging the Gap between Research and Practice. In: in Proceedings of the 5th International Conference on the Practice and Theory of Automated Timetabling, Springer, pp. 15–35.
Müller, T., Rudova, H., & Müllerova, Z. (2018). University course timetabling and international timetabling competition 2019. In: Proceedings of the 12th International Conference of the Practice and Theory of Automated Timetabling (PATAT 2018), Vienna, Austria, pp. 5 – 31.
Paechter, B., Gambardella, L.M., & Rossi-Doria, O. (2002). The first international timetabling competition. URL http://www.idsia.ch/Files/ttcomp2002/(2002)
Plaisted, D. A., & Zaks, S. (1980). An NP-complete matching problem. Discrete Applied Mathematics, 2(1), 65–72.
Rudova, H. (2015). University course timetabling—from theory to practice. In: Multidisciplinary International Scheduling Conference (MISTA 2015) (Talk), Prague, Czech Republic, URL https://www.fi.muni.cz/~hanka/publ/mista15.pdf
Schaefer, T.J. (1978). The complexity of satisfiability problems. In: Proceedings of the 10th Annual ACM Symposium on Theory of Computing, May 1-3, 1978, San Diego, California, USA, pp. 216–226, https://doi.org/10.1145/800133.804350
Schindl, D. (2019). Optimal student sectioning on mandatory courses with various sections numbers. Annals of Operations Research, 275(1), 209–221. https://doi.org/10.1007/s10479-017-2621-1.
Tanimoto, S. L., Itai, A., & Rodeh, M. (1978). Some matching problems for bipartite graphs. Journal of the ACM, 25(4), 517–525.
ten Eikelder, H. M. M., & Willemen, R. J. (2001). Some complexity aspects of secondary school timetabling problems. In E. Burke & W. Erben (Eds.), Practice and theory of automated timetabling III (pp. 18–27). Heidelberg: Springer.
Acknowledgements
We are very grateful to our anonymous reviewers for their very valuable comments.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Herres, B., Schmitz, H. Decomposition of university course timetabling. Ann Oper Res 302, 405–423 (2021). https://doi.org/10.1007/s10479-019-03382-0
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10479-019-03382-0