Assessing the impact of systems modeling in the redesign of an Emergency Department

Systems modeling has been used to redesign care in the National Health Service in the United Kingdom. However, assessing the benefits of such modeling is problematic. This paper examines the impact of two complementary techniques, process mapping and simulation, in the redesign of Emergency Department (ED) systems. Using the example of one significant change prompted by systems modeling, the introduction of a new staff roster, the impact on patient‐time in the ED is examined. Any assessment has to recognize the effect of changes in the environment, notably staff experience and volume of activity. Using a performance model that incorporates these variables, the main quantifiable impact of the new roster was identified as a reduction in the mean patient‐time of 16min, for the 87% of ED patients classified as minor. Attributing credit for any improvement requires care but systems modeling can provide valuable insights into the design of ED systems resulting in quantifiable improvements.