Analysis of min-max ambulance diversion policies using queuing theory

Ambulance Diversion is a method applied by decision makers in Emergency Departments to relieve congestion from their facilities. It is a challenging task to make the decision since there exists some trade offs. For example, diverting ambulances from an overcrowded emergency department could reduce the waiting time of accepted patients in the long term; however, managers may want to minimize the time spent on diversion due to risks of patient condition deterioration from the longer transportation and due to reputation loss. This paper analyzes the impact of ambulance diversion policies based on min-max rules on conflicting performance measures. Models based on queuing theory are applied to analyze solutions in bi-criteria space under different congestion levels and consideration of the sensitivity of input parameters.