Column generation algorithms for the capacitated m-ring-star problem

Abstract

In this paper we propose an integer programming formulation for the capacitated m-ring-star problem (CmRSP) based on a set covering model and develop an exact branch-and-price (BP) algorithm to solve it exactly. The is a variant of the classical one-depot capacitated vehicle routing problem in which a customer is either on a route or is connected to another customer or to some connection point present in a route. The set of potential connection points and the number m of vehicles are given a priori. Routing and connection costs are also known and the goal is to minimize the sum of routing and connection costs. To our knowledge, the only exact approach for the is a branch-and-cut (BC) proposed in [2]. Extensive experimentation reported here shows that our algorithm is competitive with the algorithm. This performance was achieved after a profound investigation of the alternatives for column generation relaxation and a careful implementation of the pricing algorithm. © 2008 Springer-Verlag Berlin Heidelberg.