The French Emergency Medical services, which are known as SAMU (the acronym of Urgent Medical Aid Services in French), are public safety systems responsible for the coordination of pre-hospital care under emergency conditions throughout a particular geographic region. The goal of these systems is to respond in a timely and adequate manner to population calls, to provide first-aid services and to transfer patients to the appropriate care facility when needed. The current study aims to develop the process of the Val-de-Marne department's SAMU system (SAMU 94) in an efficient manner that meets the population's needs using limited resources. For this purpose, we propose a discrete event simulation (DES) model implemented in the ARENA software to analyze possible changes in the SAMU 94 processes that would lead to enhanced operational efficiency for coverage performance (i.e., the percentage of calls for which the patient wait time before a SAMU 94 rescue team arrives does not exceed a specific target time). Hence, the model enables to test five categories of scenarios that are mainly related to the level of resources used as well as the location of rescue teams throughout the service area. Among other results, we found that repositioning a portion of the existing teams into potential bases increased the 20-min coverage performance up to 4.5% in average. Furthermore, this improvement in coverage can reach 7.3% when the whole fleet is relocated based on the multi-period redeployment plan obtained from simulation optimization.