The decision method of emergency supplies collection with fuzzy demand constraint under background of sudden disaster

As the stages of emergency response shift, it is an important task in the early stage of emergency response to handle emergency supply (ES) collection with fuzzy demand and multi-hub ES collection network. Taking into consideration the constraints such as no limit to collection time, capacity constraint to single hubs and different demand levels to be met by collection, this paper aims at establishing a mathematic planning model with two objectives, namely the shortest collection time and the optimal collection cost. In terms of algorithm design, the sequential enumeration method (SEM) was employed to solve the model, for higher iteration efficiency and lower difficulty level of the algorithm. The first step was to find the optimal ES collection time, collection route and allocation program in the direct shipment mode, the hub-and-spoke mode and the mixed mode. Then, the three modes were compared in terms of the collection route planning, the shortest collection time, the shortest collection route and the optimal collection cost of the entire ES collection network. The numerical example showed that compared with the simulated annealing (SA) algorithm, the result of SEM is basically the same with that of SA algorithm; however, SEM is simpler, more practical and easier to operate, so that it is of better promotional value.