Locating Distribution Centers and Vehicle Routing in the disaster condition using two-stage programming

Natural disasters have increased in recent decades and the issue of locating and routing have been identified and introduced as the most important issues in crisis situations. This importance is due to the fact that if the relief facilities are located correctly, it will be possible for the injured to have easier access to these facilities. On the other hand, the correct routing of vehicles will prevent waste of time due to their very significant role in times of crisis. Therefore, the present study used a two-stage model of locating and routing in crisis situations. In the first stage of the model, the decision maker is responsible for selecting the location of distribution centers from among the available candidates and in the second stage, the best route of transportation with the shortest distance should be identified due to time limit. In this regard, to show the efficiency and evaluation of the proposed model, several problems have been solved definitively and different sensitivities have been analyzed on its effective parameters. The results showed that the two effective factors of capacity and coverage radius were the parameters that had the greatest impact on the model.