Overlong waiting time in emergency services is an important matter which has negative influence on healthcare quality. This problem can be resolved by improving emergency services using modelling and discrete event simulation of system process. In this article, a simulation model is designed to represent the patient visit process by using, respectively, IDS Scheer ARIS™ and Rockwell Arena™. This simulation model can help us to identify process bottlenecks, and adjust resources allocation or staff dimensioning without disturbing the actual system. For the purpose of reducing waiting time in emergency departments (ED), doctor's efficiency improvement and quick pass process are proposed and experimented as two new solutions. In addition to simulation results, we summarise some advantages and shortcomings observed during our development work for future use of ARIS and Arena. This work was based on the ED at Saint Joseph and Saint Luc Hospital in Lyon, France.