A multi-class queuing network analysis methodology for improving hospital emergency department performance

This paper derives an open queuing network model of an emergency department (ED) design intended to increase the capacity of an ED to treat patients. The methodology captures hospital-specific differences in patient acuity mix, arrival patterns and volumes, and efficiencies of processes in a single common computational model. A spreadsheet implementation of the resulting queuing equations is used by managers, in real time, to size ED areas using waiting time and overflow probability as quality of service targets. Non-homogeneous arrival patterns, non-exponential service time distributions, and multiple patient types are all incorporated. The methodology has been applied to a fleet of hospitals for validation. Results from one of them are used to demonstrate the methodology.Scope and purposePopulation growth, closure of emergency departments (EDs) nearby, or seasonal peak variation can cause ED patient wait times to increase dramatically. Prolonged waits induce patients to leave the ED before receiving treatment, creating a public health problem. The purpose of this paper is to introduce a new paradigm of ED care that reduces “walk-aways”, and increases ED access, through an operational research method that customizes to any hospital through the use of hospital-specific data elements.