SysML for conceptual modeling and simulation for analysis: A case example of a highly granular model of an emergency department

Continual improvements to the efficiency of patient flow in emergency departments (EDs) are necessary to meet patient demand. Discrete Event Simulation (DES) is commonly employed for this purpose, but validation and verification is daunting in that many stakeholders - clinicians, administrators, and engineers - need to understand the system´s processes in a unified manner. Therefore, knowledge transfer between stakeholders requires a unified formal approach. We describe the use use of System Modeling Language (SysML) to this end, as well as the results of model validation by comparing hourly census in many areas in the real-world ED with those predicted from simulation, before and after a process intervention. The accuracy of these comparisons provides evidence that a methodologically rigorous DES model, incorporating our method for model verification using SysML, is a valuable decision making tool for judging the utility of interventions to improve patient flow.