Resource modeling in discrete-event simulation environments: A fifty-year perspective

Through 50 years of innovation, discrete-event simulation environments have offered similar approaches to modeling the resources that participate in simulations. These approaches involve ¿clients¿ and ¿servers¿ of varying activity levels that wait in queues of varying sophistication. While powerful enough for many applications, these models limit the complexity of the entities that may be represented. Analysis of more than thirty simulation environments provides the substrate for defining ¿levels¿ of modeling features from primitive foundations to advanced embellishment. This analysis not only supports comparison of existing resource models, but also informs the development of new approaches.