جستجوی مقالات مرتبط با کلیدواژه « multi-layer service » در نشریات گروه « صنایع »

In this paper, we investigate location-allocation problem for multi-layer congestible facilities. In many real word location situations, a service center is not capable of serving all the simultaneous requests made for the service and as a result forming queues and congestion is inevitable. For this purpose, a multi-objective nonlinear integer programming model for queuing facility location problem with the same framework to the M/M/1 series queuing network is designed, in which facilities have several layers and customers should pass all the layers for service completion. The objective functions of the model are minimizing the sum of customers traveling times to facilities and waiting times in the system, and minimizing the maximum idle probability of the facilities. The proposed mathematical model is validated by sensitivity analysis, and the effect of the probable variations of the parameters on the Pareto solution is investigated. The results show that the model behaves correctly to the sensitive parameters of the problem. To evaluate the model, some numerical experiments are presented and solved with the Augmented ε-‏constraint technique of multi-objective optimization as well. The appropriate location among potential sites for appropriate number of facilities and allocation of customers to facilities of each layer are determined by Pareto optimal solutions found.