The availability of emergency medical services for the public is a crucial point in urban infrastructures. One quality factor for emergency medical services is the lapse of time between an emergency call and the arrival of an emergency vehicle on the spot, which is impacted by the number of emergency vehicles available in a given area as well as by their location. Due to budget restrictions, public organizations are obliged to appoint their resources efficiently while keeping its duty to provide the best possible service in mind. The location-planning becomes especially important in major cities with a big population and a high demand for medical services. This paper compares 3 different location models in order to determine the best location policy for emergency vehicles based on real data for city of Vienna.