Integer and combinatorial optimization
Integer and combinatorial optimization
Shared storage policies based on the duration stay of unit loads
Management Science
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Generalized Assignment Problems
ISAAC '92 Proceedings of the Third International Symposium on Algorithms and Computation
A Multicommodity Network-Flow Problem with Side Constraints on Paths Solved by Column Generation
INFORMS Journal on Computing
Models and Tabu Search Heuristics for the Berth-Allocation Problem
Transportation Science
The Berth Allocation Problem: A Strong Formulation Solved by a Lagrangean Approach
Transportation Science
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This paper studies the dynamic generalized assignment problem (DGAP) which extends the well-known generalized assignment problem by considering a discretized time horizon and by associating a starting time and a finishing time with each task. Additional constraints related to warehouse and yard management applications are also considered. Three linear integer programming formulations of the problem are introduced. The strongest one models the problem as an origin-destination integer multi-commodity flow problem with side constraints. This model can be solved quickly for instances of small to moderate size. However, because of its computer memory requirements, it becomes impractical for larger instances. Hence, a column generation algorithm is used to compute lower bounds by solving the linear program (LP) relaxation of the problem. This column generation algorithm is also embedded in a heuristic aimed at finding feasible integer solutions. Computational experiments on large-scale instances show the effectiveness of the proposed approach.