An Interactive Tool for the Controlled Execution of an Automated Timetabling Constraint Engine

  • Alberto Delgado
  • Jorge Andrés Pérez
  • Gustavo Pabón
  • Rafael Jordan
  • Juan F. Díaz
  • Camilo Rueda
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3389)


Here we introduce DePathos, a graphical tool for a time-tabling constraint engine (Pathos). Since the core of Pathos is text-based and provides little user-interaction, finding an appropriate solution for large problems (1000-2000 variables) can be a very time consuming process requiring the constant supervision of a constraint programming expert. DePathos uses an incremental solution strategy. Such strategy subdivides the problem and checks the consistency of the resulting subdivisions before incrementally unifying them. This has shown to be useful in finding inconsistencies and discovering over-constrained situations. Our incremental solution is based on hierarchical groupings defined at the problem domain level. This allows users to direct the timetabling engine in finding partial solutions that are meaningful in practice. We discuss the lessons learned from using Pathos in real settings, as well as the experiences of coupling DePathos to the timetabling engine.


Time Slot Constraint Programming Real Setting Schedule Process Timetabling Problem 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Boufflet, J.P., Nègre, S.: Three methods used to solve an examination timetable problem. In: Burke, E.K., Ross, P. (eds.) PATAT 1995. LNCS, vol. 1153. Springer, Heidelberg (1996)Google Scholar
  2. 2.
    Elmohamed, M.A.S., Coddington, P., Fox, G.: A comparison of annealing techniques for academic course scheduling. In: Burke, E.K., Carter, M. (eds.) PATAT 1997. LNCS, vol. 1408, p. 92. Springer, Heidelberg (1998)CrossRefGoogle Scholar
  3. 3.
    Fruhwirth, T., Abdennadher, S.: Essentials of Constraint Programming. Springer, Heidelberg (2002)Google Scholar
  4. 4.
    Geller, S.: Timetabling at the University of Sheffield, UK - an incremental approach to timetable development. Practice and Theory of Automated Timetabling (2002)Google Scholar
  5. 5.
    Henz, M., Wurtz, J.: Using oz for college timetabling. In: International Conference on the Practice and Theory of Automated Timetabling (1995)Google Scholar
  6. 6.
    Kaneko, K., Yoshikawa, M., Nakakuki, Y.: Improving a heuristic repair method for large-scale school timetabling problems. In: Jaffar, J. (ed.) CP 1999. LNCS, vol. 1713, pp. 275–288. Springer, Heidelberg (1999)Google Scholar
  7. 7.
    Legierski, W.: Using Mozart for Timetabling Problems. In: Proceedings of the CPDC 2001 Workshop on Constraint Programming for Decision and Control (2001)Google Scholar
  8. 8.
    Marte, M.: Models and Algorithms for School Timetabling - A Constraint-Programming Approach. Dissertation/Ph.D. thesis, Institute of Computer Science, LMU, Munich (2003)Google Scholar
  9. 9.
    Pabón, G., Rodriguez, C.: Reingeniería de PATHOS (In Spanish). B.Sc. Thesis - Universidad Javeriana, Cali (2003), Available at
  10. 10.
    Rich, D.C.: A Smart Genetic Algorithm for University Timetabling. In: Burke, E.K., Ross, P. (eds.) PATAT 1995. LNCS, vol. 1153, pp. 181–197. Springer, Heidelberg (1996)Google Scholar
  11. 11.
    Rueda, C., Díaz, J.F., Quesada, L.O., García, C., Cetina, S.: Pathos: Object-oriented concurrent constraint timetabling for real world cases. In: Proceedings, XXVIII Latin-American Conference on Informatics, Uruguay (2002)Google Scholar
  12. 12.
    Wasacz, D.: Timetabling with CHIP. In: Proceedings of the CPDC 1999 Workshop on Constraint Programming for Decision and Control (1999)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Alberto Delgado
    • 1
  • Jorge Andrés Pérez
    • 1
  • Gustavo Pabón
    • 3
  • Rafael Jordan
    • 1
  • Juan F. Díaz
    • 2
  • Camilo Rueda
    • 1
  1. 1.Pontificia Universidad JaverianaCali
  2. 2.Universidad del Valle 
  3. 3.Central Planning Software 

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