The hierarchical hub covering problem with an innovative allocation procedure covering radiuses

Hub location problems deal with locating hub facilities at one level of services or one type of facility, but some systems are performed by several types of facility. So, this paper attempts to study a single allocation hierarchical hub covering a facility location problem over a complete network linking at the rst level, which consists of hub facilities known as central hubs. In addition, the study proposes a mixed integer programming formulation and nds the location of the hubs at the second level and central hubs at the rst level, so that the non-hub and hub nodes are allocated to the opening hub and central hub nodes. Thus, the travel time between any origin destination pair is within a given time bound. The current study presents an innovative method for computing the values of radiuses in order to improve the computational time of the model and to test the performance of the mentioned heuristic method on the CAB data set and on the Turkish network. Helpful results were obtained, including: severe reduction in the time of solution, rational distribution of the centers for presenting results, equality (Justice) and appropriate accessibility consistent with dierent levels of servicing. A computational experience was applied to the Iranian hub airport location.