Aggregate model based performance analysis of an emergency department

In this paper we present an aggregate simulation model for a real-life emergency department, which is based on the concept of effective process times and which uses a token system to model patients claim- ing multiple resources simultaneously. Although it has been developed for a specific hospital, the model is exible, and capable to describe different set- Tings. The modeling steps, model specification and model validation are explained in detail. By using a process-based simulation language, the resulting model is transparent, intuitive and easy to use in quantitatively evaluating proposed changes in the operational processes of the emergency department.