One of the cornerstones to performance-based design (PBD) is the assessment of occupant evacuation times from a building in the event of a fire. Considerable progression in the capabilities of egress modeling has led to a fairly comprehensive range of assessment tools for fire protection engineers to evaluate occupant evacuation. Rapid advancements in computer technology have resulted in noticeable improvements in current evacuation software including faster computing times, increased visualization, and simpler user interfaces. Some models also integrate many user options in attempt to predict human behavior within the fire environment. These sophisticated models simplify a complex and dynamic aspect of occupant evacuation for the user. It is implied that with greater complexity and range of assessment options built into the model comes improved accuracy and higher confidence in the results, which are in turn dependent on the assumptions made and parameters selected by the user. This paper assesses the application of available modeling techniques to a high occupancy evacuation scenario. A case study will be evaluated using hand calculation methods, network flow models and behavioral simulation models. Input parameters to the respective methods will be varied, within appropriate ranges from evacuation literature, to ascertain the significance of assumptions made on the total evacuation time. The variance of parameters will be compared within each method and compared individually across the different simulation methods. The focus of this study is to highlight the dependence of current evacuation modeling methods on the user inputs, therefore providing users with a better understanding and awareness of how the evacuation time can vary when these parameters are altered.