A Theory-based Conceptual Terminology for M & S VV & A

The DEVS (Discrete Event System Specification) is a sound formal Modeling and Simulation framework based on generic dynamic systems concepts. DEVS is a mathematical formalism with well defined concepts of coupling of components, hierarchical, modular construction, support for discrete event approximation of continuous systems and an object-oriented substrate supporting repository reuse. Despite the variance with other terminologies widely prevalent in the DoD M&S community, we propose that there are advantages for VV&A to be gained by adopting the theory-based definitions. These advantages include well-defined separation of concerns supporting distinct modeling and simulation layers that can be independently verified and reused in later combinations with minimal re-verification. The resulting divide and conquer approach can greatly simplify and accelerate VV&A leading to greater credibility at reduced effort. An example involving verification of the implementation of the DEVS/HLA environment is given to illustrate these points.