The single-allocation hierarchical hub median location problem with fuzzy demands

Although, many papers have appeared in the literature of hub location problem, most of them deal with the problem in a crisp environment. In this paper, the single-allocation hierarchical hub median problem (SA-H-MP) with fuzzy demands is addressed. The structure of the model is derived from Yaman (2009) and consists of a three-level network of demand nodes, non-central hubs, and central hubs. It has been assumed that the demands are not known precisely and are estimated using fuzzy variables. In order to solve the problem, a simulation-embedded variable neighborhood search (VNS) is applied. The results of running the proposed approach on the well-known CAB dataset verify that it is able to solve test problems with less than one percent of error.