The paper presents a comprehensive research study on the Simulation Model for Emergency Department. The study was conducted in the Emergency Department (ED) at The Ohio State Medical Center. A simulation model was developed using Arena (7.0) to model the process flow of patients in order to analyze the ED System performance. A Statistical Design of Experiments study was performed to study the significance/ non significance levels in order to improve ED performance.
Key Words: Emergency Department, Simulation, Work Flow.
1 - INTRODUCTION
The Emergency Department (ED) at Ohio State Medical Center specializes in the treatment of critically ill and seriously injured patients and possess a comprehensive array of the most up to date diagnostic and treatment services coupled with a highly trained and experienced health care staff. It was observed that the overall time patients spent in the Emergency Department of the hospital was significantly higher (500 minutes) than the benchmarked time for the patient length of stay (LOS). This has an adverse impact on patient throughput in the ED. If the patient length of stay in the ED is high, then the waiting times for new incoming patients in the ED is high and the in-process patient volumes who have received partial medical service in the ED is also high. These factors contribute to a significant decline in the ED system performance.
The objective of our research study was to analyze and evaluate ED system performance. The research study was conducted in several phases. The first phase involved construction of a detailed flow chart of the “As Is” ED system. This enabled us to understand the work flow of patients, physicians and nurses in the ED system. The second phase involved construction of a detailed simulation model using Arena (7.0). The simulation model calculates the performance evaluation measures such as total patient length of stay, total patient throughput, waiting times in the system, resource utilization, etc. The simulated values are compared with the benchmarked values and the values observed when the work sampling studies were conducted. The simulation model helped us to understand the ED system dynamics and was an invaluable tool for evaluating the variations in the performance measures.
We propose Lean methodologies to optimize the performance of the Emergency Department. The lean management based methodologies were embedded in the simulation model in to obtain the ED system performance measures. The simulated measures of performance were tabulated and a statistical Design Of Experiments (Analysis of Variance) was performed in order to obtain significant and non- significant factors in the study.
2 LITERATURE REVIEW
Samaha and Armel (2003) present a simulation model and a complete analysis of operations in the Emergency Department of Cooper University Hospital, which is a 554-bed licensed facility. Miller and Ferrin (2003) simulated a large hospital in South East USA and proposed Six Sigma-based process improvement ideas for reduction of patient length of stay.. Garcia et al. (1995) analyzed the flow of patients at the Mercy Hospital with the objective being to minimize the waiting times of patients. The above papers describe a simulation model of the Emergency Department but do not describe adequate policies and recommendations to improve the performance of the Emergency Department. A through statistical analysis is not conducted to identify significant and non- significant factors impacting the ED performance.
Centeno et al. (2003) observed in their study at the Baptist Health South Florida that one of the significant operating costs in the Emergency rooms is the staffing costs. Baesler et al. (2003) have developed a simulation model for calculating the maximum possible demand increment in an Emergency room of a private hospital in Chile. The simulation...