A Maximal Covering Location Model of Ambulances in Emergency Medical Service

Emergency medical service (EMS), known as one of the most important health care services, plays a vital part in saving people's lives. Among the EMS problems, deployment of ambulances is a hot issue. A lot of research has done from different aspects to find a better plan on ambulance deployment. This paper is going to solve the maximal covering location problem using an improved Double Standard Model, considering the probability that an ambulance is not available all the time. The model is applied to the data from Songjiang District, Shanghai, and we obtain deployment schemes under different probability. The demand covered by at least two working ambulances increases by using our solution.