A Variable Neighborhood Search Algorithm for Network Expansion Deferment in a Hub Network

Abstract

The hub network expansion problem over planning horizon is addressed in this paper. In the extensive literature on hub network problem, it has widely been assumed that all P hub facilities must be located in current period and they do not take into account variation of demands, investment opportunities and net present cost. In this study, it is supposed that P hub facilities should have been located over planning horizon under variation of demands of every pair of nodes over time periods and also considering congestion effects at hub nodes. In this study, a mixed integer nonlinear programming formulation which minimizing the net present cost of planning horizon is presented. The Variable Neighborhood Search (VNS) algorithm is developed and successfully solved many instances of standard Childhood and Beyond (CAB) dataset and the results verify applicability of the proposed model and algorithm.