Date of Award

Spring 2010

Document Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

Dahai Liu, Ph.D.

Committee Member

Shawn Doherty, Ph.D.

Committee Member

Massoud Bazargan, Ph.D.


This study utilized the discrete-event simulation (DES) approach to optimize the daily tutor cost for the Unified Tutoring Center, located at the Daytona Beach campus of Embry-Riddle Aeronautical University. The simulation model was built using Arena version 12, and the objective of the study was to determine an optimum tutor staffing schedule to minimize operating costs, while also servicing as many students as possible and with the students experiencing a minimal wait time. Data was collected by videotaping four weeks (or 20 nights) worth of evening tutoring sessions, held Sunday through Thursday between 6-9pm. Two models, the General Study Room and the Physics & Chemistry Lab, were validated by comparing the observed tutor utilization with the model's output utilization. A sensitivity analysis was conducted on both models using constrained optimization, based on average wait time, maximum wait time and maximum tutor utilization. A more practical tutor staffing schedule was found for the General Study Room and the Physics & Chemistry Lab, yielding an overall decrease in the weekly operational cost of tutors by $204.00. These results are discussed and conclusions are given at the end of this paper.