Emergency Room Model

Model Description

The administrators of an Emergency Room (ER) need to find the optimal staffing levels. The ER must be able to treat its patients in a timely manner, yet not be overstaffed (which costs the hospital a lot of money). Therefore, a simulation model of the ER was built in SIMPROCESS in order to find these optimal staffing levels.

The simulation model diagramed the current process (As-Is). Patients arrive to the ER either through the entrance door or via ambulance. The hospital groups these patients into 3 categories: level 1, level 2, and level 3. Level 1 patients, such as heart attacks victims, are considered the most critical and need to be treated immediately. Level 2 and 3 patients go through a triage process where the hospital makes an initial assessment of their injuries. All patients are then transferred to an available room for treatment. They also go through a registration process either before or after treatment, depending on the severity of their injury. After initial medical treatment, the hospital can release the patient, or assign them to a room in the hospital for a longer stay.

Hospital Copyright: <a href='http://www.123rf.com/profile_ppbig' srcset= / 123RF Stock Photo” width=”190″ height=”190″>


The ER needs to be adequately staffed to meet the numbers of incoming patients. Historical data was used to simulate the number of incoming patients, broken out into arrivals by day, evening, and morning, and the severity of their injuries. To satisfy these arrivals, some of the resources have fixed levels: 1 Charge Nurse, 1 Triage Nurse, and 13 wheelchairs. However, the other resources do not have fixed levels, and the SIMPROCESS model was used to find the optimal levels for each given the following constraints:

  • Administrative Clerks: Min 1, Max 4
  • Nurses: Min 1, Max 7
  • Patient Care Technician (PCT): Min 1, Max 4
  • Physicians: Min 1, Max 6
  • Emergency Rooms: Min 1, Max 20
In order to find the optimal levels of these resources, the SIMPROCESS optimization tool, OptQuest® (link to Optimization with OptQuest page), was applied to the ER model. The objective for OptQuest was to “maximize the rooms in use”, which would in effect reduce the number of unneeded resources and rooms. OptQuest ran 15 iterations of the ER model, and the optimal results were as follows:
  • Administrative Clerks = 3
  • Nurses = 6
  • Patient Care Technician (PCT) = 4
  • Physicians = 5
  • Emergency Rooms = 15
The hospital applied those staffing levels to the ER model and was able to determine the associated cost. In addition, a SIMPROCESS Dashboard was used to graphically illustrate the proposed staffing levels by showing the “Room Usage” and “Number of Patients Waiting”. The Dashboard clearly showed the ER’s resources would provide timely and appropriate service for all incoming patients.

Demonstration Model

In order to view the demonstration model you must have SIMPROCESS installed on your computer and you must have a license. If you don’t have SIMPROCESS you may download a trial version.

You must save the demo model file by RIGHT CLICKING on the file below and select “Save Target As”. Save the file to your computer. After you launch SIMPROCESS select File and Open. Then navigate to where you saved the demo file and select to open it.

Additional demonstration models are in the models/Demos directory which is located in the SIMPROCESS working directory.