We propose a metaheuristic algorithm for the multi-resource generalizedassignment problem (MRGAP). MRGAP is a generalization of the generalized assignmentproblem, which is one of the representative combinatorial optimization problems knownto be NP-hard. The algorithm features a very large-scale neighborhood search, which is amechanism of conducting the search with complex and po...

This paper considers the VRP Problem with Soft Time-Windows (VRPSTW), a challenging routing problem due to its combination of hard time windows and a lexicographic objective function minimizing the number of vehicles, the violations of the soft time windows, and the total travel distance. The paper presents a multi-stage, variable neighborhood search algorithm for the VRPSTW, which uses the sam...

In this paper, we introduce a hybrid metaheuristic, the Variable Neighborhood Particle Swarm Optimization (VNPSO) algorithm, consisting of a combination of the Variable Neighborhood Search (VNS) and Particle Swarm Optimization(PSO). The proposed VNPSO algorithm is used for solving the multi-objective Flexible Job-shop Scheduling Problems (FJSP). Flexible job-shop scheduling is very important in...

Large-scale multi-objective optimization problems (LS-MOP) are complex problems with a large number of decision variables. Due to its high-dimensional decision space, LS-MOP poses a significant challenge to multi-objective optimization methods including multiobjective evolutionary algorithms (MOEAs). Following the algorithmic framework of multiobjective evolutionary algorithm based on decomposi...

Industrial optimization applications must be robust: they must provide good solutions to problem instances of different size and numerical characteristics, and must continue to work well when side constraints are added. A good testbed for constructing such a robust solver is a set of network design problem instances recently made public by France Telecom. Together, these instances comprise the ...

We present Tabu Search based solution heuristics for the Timber Transport Vehicle Routing Problem (TTVRP) that differ with respect to solution space. The TTVRP is characterized as follows: a fleet of m log-trucks which are situated at the respective homes of the truck drivers has to fulfil n transports of round timber between different wood storage locations and industrial sites. All transports...

We propose a tabu search meta-heuristic for the Time dependent Multi-zone Multi-trip Vehicle Routing Problem with Time Windows. Two types of neighborhoods, corresponding to two decision sets of the problem, together with a strategy controlling the selection of the neighborhood type for particular phases of the search, provide the means to set up and combine exploration and exploitation capabili...