A Cost-Regular Based Hybrid Column Generation Approach

Abstract. Constraint Programming (CP) offers a rich modeling language of constraints embedding efficient algorithms to handle complex and heterogeneous combinatorial problems. To solve hard combinatorial optimization problems using CP alone or hybrid CP-ILP decomposition methods, costs also have to be taken into account within the propagation process. Optimization constraints, with their costbased filtering algorithms, aim to apply inference based on optimality rather than feasibility. This paper introduces a new optimization constraint, cost-regular. Its filtering algorithm is based on the computation of shortest and longest paths in a layered directed graph. The support information is also used to guide the search for solutions. We believe this constraint to be particularly useful in modelling and solving Column Generation subproblems and evaluate its behaviour on complex Employee Timetabling Problems through a flexible CP-based column generation approach. Computational results on ge...

• Type: Journal
• Year: 2006
• Where: CONSTRAINTS
• Authors: Sophie Demassey, Gilles Pesant, Louis-Martin Rousseau
• Keywords: CONSTRAINTS 2006, Filtering Algorithm, Heterogeneous Combinatorial Problems, Optimization Constraint