$$\pi $$ HyFlow: formalism, semantics, and applications

Simulation models have been described using different perspectives, or worldviews. In the process interaction world view (PI), every entity is modeled by a sequence of actions describing its life cycle, offering a comprehensive model that groups the events involving each entity. In this paper we describe \(\pi \) HyFlow, a formalism for representing hybrid models using a set of communicating processes. This set is dynamic, enabling processes to be created and destroyed at runtime. Processes are encapsulated into \(\pi \) HyFlow base models and communicate through shared memory. \(\pi \) HyFlow, however, can guarantee modularity by enforcing that models can only communicate by input and output interfaces. \(\pi \) HyFlow extends current PI approaches by providing support for HyFlow concepts of sampling and dense (continuous) outputs, in addition to the more traditional event-based communication. Likewise HyFlow, \(\pi \) HyFlow is a modeling & simulation formalism driven by expressiveness and performance analysis. We present \(\pi \) HyFlow semantics, and several applications to illustrate \(\pi \) HyFlow ability to describe a diversity of systems.