Infrastructure planners need new methods to exchange technical data in the pursuit of long-term and cross-sector objectives including sustainability. This paper demonstrates a method for infrastructure system simulation interoperability by applying the high-level architecture (HLA) to the infrastructure system of systems (ISoS) modeling framework. The ISoS considers time-aggregated simulations with iterative data exchange periods to resolve cyclic dependencies. Applying the HLA defines object models, operational agreements, federate implementations, and physical infrastructure required for a federated simulation. An example demonstrates the method on a scenario with 18 infrastructure elements across water, electricity, petroleum, and social sectors as individual federates.
The cost of interoperability arises from network latency, runtime infrastructure (RTI) overhead, and additional development effort. Results across several RTIs show that a distributed simulation requires 10–100 times longer executions than noninteroperable configurations. Analysis of source code shows that the HLA contributes about 1500 (56%) more software lines of code to implement federation object models and agreements. The value of interoperability arises from new capabilities provided by the HLA: physical distribution and independent control of constituent models. Conclusions describe a role for the HLA in model-based concept exploration during collaborative and interorganizational design activities with live human participation similar to its use for wargames.