Heterogeneous actor modeling

Complex systems demand diversity in the modeling mechanisms. This “roadmap” paper prescribes an approach to modeling based on concurrent communicating components (called actors), where a diversity of orchestration strategies govern the execution and interaction of the components. The prescribed approach has been extensively explored in the Ptolemy Project, but as yet is not widely deployed in engineering practice. The approach achieves interaction between diverse models using an abstract semantics, which is a deliberately incomplete semantics that cannot by itself define a useful modeling framework. It instead focuses on the interactions between diverse models, reducing the nature of those interactions to a minimum that achieves a well-defined composition. The actor semantics is an abstract semantics that can handle many heterogeneous models that are built today, and some that are not common today. The actor abstract semantics and many concrete semantics are implemented in Ptolemy II, an open-source software framework.