A simulation–optimization approach for measuring emergency department resilience in times of crisis

Crisis occurrence in the healthcare context is, for different reasons, a phenomenon that happens abundantly. The priority of the healthcare system during a crisis is to provide quality care and superior services to the injured people. However, given the usually extreme severity of the crisis that results in a significant number of injured people, proper and timely responsiveness of healthcare systems is a challenging issue This study proposes a novel framework using a hybrid simulation–optimization approach to measure the healthcare responsiveness in crisis to address this real-world problem. This paper closely connects operations research techniques to critical systems thinking notions to evaluate the behavior of a system in the face of crisis. Since all arriving casualties to the hospital are first taken to the emergency department (ED), the ED in a case study is used to illustrate the performance of the presented approach. We designed seven crisis scenarios and one scenario of the ED system in a normal situation and modeled them using discrete-event simulation (DES). Patients’ interarrival times act as the driver of workload experienced in ED during crisis scenarios of varying severity. For crisis simulation scenarios that are unable to cope with the severity of the crisis, we developed an optimization model in an optimization tool to determine the optimal configuration of resources. The optimal configuration can improve healthcare resilience. The results show that an interarrival time of 13.8 min is the maximum threshold, below which feasible solutions could not be found, and the ED system is likely to collapse.