This thesis identifies various material handling model parameters which must be addressed when using simulation. Operations of six material handling devices (AGVS, AS/RS, conveyors, cranes, fork trucks, and industrial robots) are studied to determine attributes which require modeling consideration. Four simulation software packages (GPSS, PROMODELPC, SIMAN IV, and SLAM II) are analyzed to determine their capabilities for modeling material handling situations. A survey was developed to extract information, from software experts, about each software package under study. Based on this survey, the state-of-the-art in modeling materials handling systems is assessed. / Master of Science