A DEVS Modeling and Simulation Framework Based DEVS Formalism and Object-oriented Methodology

This article describes a DEVS modeling and simulation framework based on DEVS formalism and object-oriented methodology (Simu Class), which not only realizes the DEVS formalism and its related hierarchical simulation algorithms under Visual C⁺⁺ environment, but also integrates with two powerful system developing frameworks-the DEVS formalism and the object-oriented paradigm. Developing the reusable simulation model is always an important research subject in computer simulation technology. Hierarchical modeling method provides a foundation to develop reusable simulation model. In this modeling, higher layer model includes lower layer models as components. The higher layer model includes all linkage information among the components and itself. Bigger model can also be structured by the higher layer model as a component. SimuClass supports the development of the discrete event models with the application of the hierarchical medularization methods under C⁺⁺ object-oriented environment. SimuClass builds a simulation class library. Based on C⁺⁺, it has a hierarchical structure working with Atomic DEVS Model and Coupled DEVS Model. Based on the simulation class library,SimuClass builds a real DEVS system modeling development environment which provides object-oriented hierarchical modeling tools. The system defines two kinds of foundational class models: class CAtomicModel and class CCoupledModel. According with DEVS formalism CAtomicModel corresponds to Atomic DEVS, CCoupledModel to Atomic DEVS. The design of SimuClass system implies the automatic management for simulation control. For enhancing the reusability of model and supporting the object-oriented construction methodology test, SimuClass separates the model from simulation scheduler reasonably. The scheduling mechanism is invisible for the modeling builder. So that modeling builder only use the formalism with the C⁺⁺ programming (SimuClass modeling language) to describe discrete event model and develop discrete event simulation system very easily. The main advantages of the SimuClass method are that the modeling builder can fully utilize all the characteristics of the C⁺⁺ object-oriented programming and completely apply the semantics of the DEVS formalism to fulfill the reusable model development.