Constraint Programming Based Column Generation for Crew Assignment
Journal of Heuristics
A Framework for Constraint Programming Based Column Generation
CP '99 Proceedings of the 5th International Conference on Principles and Practice of Constraint Programming
A Filtering Algorithm for the Stretch Constraint
CP '01 Proceedings of the 7th International Conference on Principles and Practice of Constraint Programming
Constraint Programming Contribution to Benders Decomposition: A Case Study
CP '02 Proceedings of the 8th International Conference on Principles and Practice of Constraint Programming
Generalized arc consistency for global cardinality constraint
AAAI'96 Proceedings of the thirteenth national conference on Artificial intelligence - Volume 1
Modeling the Regular Constraint with Integer Programming
CPAIOR '07 Proceedings of the 4th international conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems
Computers and Operations Research
Reformulating Global Grammar Constraints
CPAIOR '09 Proceedings of the 6th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems
Guiding Search using Constraint-level Advice
Proceedings of the 2006 conference on ECAI 2006: 17th European Conference on Artificial Intelligence August 29 -- September 1, 2006, Riva del Garda, Italy
PATAT'06 Proceedings of the 6th international conference on Practice and theory of automated timetabling VI
CPAIOR'08 Proceedings of the 5th international conference on Integration of AI and OR techniques in constraint programming for combinatorial optimization problems
A constraint programming-based solution approach for medical resident scheduling problems
Computers and Operations Research
Retail store workforce scheduling by expected operating income maximization
CPAIOR'11 Proceedings of the 8th international conference on Integration of AI and OR techniques in constraint programming for combinatorial optimization problems
Hi-index | 0.00 |
The Employee Timetabling Problem (ETP) is a general class of problems widely encountered in service organizations (such as call centers for instance). Given a set of activities, a set of demand curves (specifying the demand in terms of employees for each activity for each time period) the problem consists of constructing a set of work shifts such that each activity is at all time covered by a sufficient number of employees. Work shifts can cover many activities and must meet work regulations such as breaks, meals and maximum working time constraints. Furthermore, it is often desired to optimize a global objective function such as minimizing labor costs or maximizing a quality of service measure. This paper presents variants of this problem which are modeled with the Dantzig formulation. This approach consists of first generating all feasible work shifts and then selecting the optimal set. We propose to address the shift generation problem with constraint satisfaction techniques based on expressive and efficient global constraints such as gcc and regular. The selection problem, which is modeled with an integer linear program, is solved by a standard MIP solver for smaller instances and addressed by column generation for larger ones. Since a column generation procedure needs to generate only shifts of negative reduced cost, the optimization constraint cost-regular is introduced and described. Preliminary experimental results are given on a typical ETP.