This research examines an approach to modeling and simulating distributed object computing systems in terms of distributed software components mapped onto a set of interconnected network nodes. The overall model of a distributed object computing system has clearly separated hardware and software components enabling co-design engineering. The software component models form a distributed cooperative object (DCO) model to represent interacting software objects. The hardware component models form a loosely coupled network (LCN) model of processing nodes, network gates, and communication links interconnecting them. The software objects of the DCO are then 'distributed' across the processors of the LCN to form a distributed object computing system (DOC) model. This approach facilitates design analysis of each of these components separately as well as the combined systems behavior. The Discrete Event System Specification (DEVS) formalism is used to implement dynamic models of the DCO components, LCN components, and experimental frames to analyze system behavior.