Application of hypercube model of queues to assess the decentralization of ambulances in an urban system of emergency medical care

One of the major concerns of urban emergency medical systems is to provide the fastest possible first care medical assistance to the victims. The response times depend on different aspects such as: local traffic conditions, weekday and time, type and number of available vehicles, location of these vehicles, dispatching policies, etc. This work analyzes the effects of decentralizing ambulances in the emergency medical system (SAMU-192) of Campinas, SP. The problem is dealt with the hypercube queuing model, which considers stochastic variations of the arrival and service processes of the emergency calls. The application of the model produces a wide variety of system performance indicators, which are compared to the actual observed values. The results obtained with ambulance decentralization showed a significant increase in the service level offered to the users.