The ISoS Modeling Framework for Infrastructure Systems Simulation

Strategic infrastructure design considers long-term and cross-sector objectives to meet societal needs. Designers rely on tools to mitigate limits on human perception and manage complex systems with high-performance requirements. This paper defines the infrastructure system-of-systems modeling framework for heterogeneous simulation models. It formally defines structural and behavioral templates and an interoperability interface using algebraic statements. Infrastructure elements are graph edges, which express functions via operational states. An interoperability interface defines requirements for resource exchanges across system model boundaries. An example application case demonstrates a model instance with 18 infrastructure elements in water, petroleum, electricity, and social system models. Results show flow validity constraint violations arise from acyclic and cyclic dependencies between models. Increasing the number of iterations per time step or shortening the time step reduces error at the cost of execution time.