In recent years, health care organizations, in particular emergency department (ED), have come under increasing pressure to provide quality care. In this context, human resources are a central aspect: a good utilization of health worker could improve quality of care. In this paper, a simulation model is proposed. The model represents an ED coupled with an optimization method to optimize the allocation of medical and para-medical human resources in the hospital center of Troyes. We aim to improve the quality of services offered to patients through the minimization of Average Waiting Time (AWT) and Average Inpatient Stay (AS). The proposed approach has proved to be effective to reduce AWT and AS by 12 minutes and 21 minutes respectively.