چكيده به لاتين
Due to the high rate of investment (approximately 30 billion tomans for each train) and also not allocating of the wagons to the maintenance procedure likewise the air transportation, railway maintenance is very substantial. Railway maintenance should not make any stop to the task and movement of train, because the stop causes customer dissatisfaction of railway systems. Also, for satisfying the customers we should respond to their demands at the minimum amount of time. Thus, in the research we consider the location routing problem integratedly, because the separation between them will lead to the local optimum solution. On the other hand, network analysis shows that different factors such as demand change, customer point transfers, government laws alternation, network cost fluctuations (such as transportation cost, warehouses, maintenance and tax costs) causes the distraction of primary network from its optimum condition. Thus, based on such incentives, it is strongly necessary to reconsider the network decisions, in this respect, redesigning various depots in railway systems, especially maintenance depots, becomes controversial. In this thesis, a scenario-based multi-period mathematical programing model in order to handle a location-routing problem of the maintenance depots of freight cars with considering the network redesign such as new depots establishments and inactivating the existing depots is presented. Considering different amount of demands during a month, we utilize the scenario-based stochastic programing approach. The model is solved in GAMS using Cplex Solver. Ultimately, to validate the effectiveness of the mathematical model, besides of solving a numerical example, we conducted a real case study of IRI railways. The results shows that three depots should be established in the cities of Ghaniabad, Kashmar and Shorgaz, and the depots of Shahrood, Zanjan, Hasanabad, Yazd and Kerman should be inactivated.
