Hierarchical Modeling and Process Aggregation in Object-Oriented Simulation

Abstract : The objective of this research is to develop techniques for more easily building simulation models with resolution levels appropriate for their purpose. The basic premise was that a modular, hierarchial modeling approach would be best suited to accomplish this and that object oriented programming techniques would be a primary enabling technology. Within the proposed hierarchial modeling framework, submodels may be represented in either their original form or in an aggregated form, the choice of being governed by the goals and constraints of a particular simulation study. In this paper a prototype hierarchial modeling system supporting aggregation is presented. The prototype was coded in the SMALL-TALK-80 object oriented programming environment, and is tailored to an airbase logistics application. The paper also discusses several possible approaches to aggregation, concluding that the simulative approach is most appropriate for this application.