A new combined dynamic location model for emergency medical services in fuzzy environment

In this paper, a new combined dynamic model for locating emergency vehicles and ambulance stations in an emergency medical service (EMS) system is presented. The proposed model can deal with the uncertainty in problem parameters. Meanwhile, the dynamic structure of the model enables EMS managers to adopt a horizon time planning approach. The model can also investigate the efficiency of EMS facilities, whereas the input and output parameters of stations are expressed as fuzzy numbers. To show the validity of the present work, a numerical example is also reported.