An open system for multiple discrete, geographically disperse simulation engines to communicate with each other across a distributed electronic network, such as the Internet, comprises a portal accessible to the simulation engines over the network. Local portions of the simulation may be run separately by each simulation engine, and the output data files are stored on and managed by the portal. A co-simulating engine may request an output data file stored by the portal and use that data as input for its downstream portion of the simulation. In this fashion, multiple geographically disperse simulation engines can test bench their designs in an open, network centric simulation environment.