Locating EMS vehicles in general networks with an approximate queueing model and a metaheuristic solution approach

Akdoğan, Muharrem Altan
In this study, problem of optimal location decision of ambulances as an server-to-customer Emergency Medical Service (EMS) vehicle is discussed. Hypercube queueing models (HQM) are employed to achieve performance measures significant to the location decision of EMS vehicles in spatial networks. Geroliminis et al(2009) extends HQM and propose Spatial Queueing Model(SQM). Our study proposes a generalization of SQM to be used in general networks. Quality of approximations inherit to SQM is questioned, and reported against various system spesific variables such as distribution of demand among regions, traffic intensity or distribution of demand regions over the area. Restriction of number of servers to be located per each location as one in the SQM model is relaxed. Effect of allowing multi servers per each location in general networks are reported. A metaheuristic algorithm (genetic algorithm) is proposed to solve the model for which no closed form expression exists and its performance is reported.