Cooperative vs non-cooperative parallelization strategies for variable neighborhood search metaheuristic: a case study on the capacitated vehicle routing problem

Abstract

The Capacitated Vehicle Routing Problem (CVRP) is a well-known NP-hard combinatorial optimization problem with numerous real-world applications in logistics. In this work, we present a literature review with recent successful parallel implementations of Variable Neighborhood Search regarding different variants of vehicle routing problems. We conduct an experimental study for the CVRP using well-known benchmark instances and we present and investigate three parallelization strategies that coordinate the communication of the multiple processors. We experimentally evaluate a non-cooperative and two novel cooperation models, the managed cooperative and the parameterized cooperative strategies. Our results constitute a first proof-of-concept for the benefits of this new parameterized cooperative approach, especially in computationally hard instances.