TY - JOUR
T1 - Integer programming techniques for educational timetabling
AU - Fonseca, George H.G.
AU - Santos, Haroldo G.
AU - Carrano, Eduardo G.
AU - Stidsen, Thomas Jacob Riis
PY - 2017
Y1 - 2017
N2 - Educational timetabling problems require the assignment of times and resources to events, while sets of required and desirable constraints must be considered. The XHSTT format was adopted in this work because it models the main features of educational timetabling and it is the most used format in recent studies in the field. This work presents new cuts and reformulations for the existing integer programming model for XHSTT. The proposed cuts improved hugely the linear relaxation of the formulation, leading to an average gap reduction of 32%. Applied to XHSTT-2014 instance set, the alternative formulation provided four new best known lower bounds and, used in a matheuristic framework, improved eleven best known solutions. The computational experiments also show that the resulting integer programming models from the proposed formulation are more effectively solved for most of the instances.
AB - Educational timetabling problems require the assignment of times and resources to events, while sets of required and desirable constraints must be considered. The XHSTT format was adopted in this work because it models the main features of educational timetabling and it is the most used format in recent studies in the field. This work presents new cuts and reformulations for the existing integer programming model for XHSTT. The proposed cuts improved hugely the linear relaxation of the formulation, leading to an average gap reduction of 32%. Applied to XHSTT-2014 instance set, the alternative formulation provided four new best known lower bounds and, used in a matheuristic framework, improved eleven best known solutions. The computational experiments also show that the resulting integer programming models from the proposed formulation are more effectively solved for most of the instances.
U2 - 10.1016/j.ejor.2017.03.020
DO - 10.1016/j.ejor.2017.03.020
M3 - Journal article
SN - 0377-2217
VL - 262
SP - 28
EP - 39
JO - European Journal of Operational Research
JF - European Journal of Operational Research
IS - 1
ER -