Introduction 1.1 Ems Process

It is generally believed that Dominique Jean Larrey (17661842) was the rst to use the wordàmbulance' (Skandalakis et al., 2006). As a surgeon of Napoleon Bonaparte's Imperial Guard, he developed a plan for rapid evacuation of wounded soldiers from the battle eld during combat using exible medical units. The term ambulance was born. The rst types of these units were pulled by horses and were used for the transportation of injured people from the battle eld and for the provision of rst aid. Nowadays, approximately 200 years later, ambulances have become common in our streets. Everybody knows what an ambulance is. However, few people are aware of the underlying processes that play a role in the planning of emergency medical services (EMS). Due to limited budgets and resources, ecient planning of ambulance services is crucial, in the medical as well as in the logistic domain. This dissertation is concerned with the latter one. To be more specic, we regard ambulance repositioning as a tool to achieve cost-eective quality of emergency care without increasing the number of ambulances on duty. To that end, we consider the ambulance relocation problem in which units may be relocated to ensure that the ability to respond to emergencies quickly is maintained in periods of decreased resource availability, i.e., when ambulances become busy. In this context, short response times, i.e., the time between the moment the emergency request is reported and the arrival of the ambulance at the emergency scene, are of utmost importance. After all, providing medical aid quickly can make the dierence between survival or death. In many countries, governments use strict response-time targets. The fraction of highest emergency calls responded to within some time threshold is widely used as perhaps the most important quantitative performance indicator for the evaluation of ambulance service providers. Strongly related to this performance measure is the coverage concept. Coverage utilizes a time standard (also called coverage radius) for service delivery. All demand areas that can be reached by an ambulance within this threshold are considered to be covered. One may interpret this coverage as thèpreparedness' of the EMS system to respond to future calls, and therefore one may solve the ambulance relocation problem by relocating ambulances in such 2 Introduction Figure 1.1: EMS process. a way that an acceptable coverage level of the region is ensured. The core of EMS operations is the EMS process. This process consists …