Using general modeling conventions for the shared development of building performance simulation software

The building performance simulation community ap-plies theory from several different fields to develop models for heat transfer, light propagation, human be-havior, and other domains. To integrate these models, we propose the adoption of general modeling conven-tions from the less familiar field of modeling and sim-ulation theory. The conventions we explore are known as the Discrete Event System Specification (DEVS). With DEVS, a model-independent simulator responsi-ble for advancing time alleviates many of the techno-logical difficulties involved in coupling models. We show how DEVS, from a mathematical perspective, accommodates the co-simulation strategies known as loose and strong coupling as well as strategies involv-ing variable time steps. We also show how a model based on a functional decomposition of a system, as opposed to a topological decomposition, readily sup-ports the sharing of domain-specific algorithms. The examples presented were implemented using Design-DEVS, an environment we created to help communi-ties of researchers collaborate in the development of simulation software.