System Modeling for V&V

Simulation and formal models are becoming an accepted part of the early stages of system design. This paper discusses the use of executable system models during system design and implementation. RTI recently developed an abstract executable model of the operating system developed for an avionics test bed based on the PAVE PILLAR architecture. The target hardware consisted of two processing clusters, each with five VHSIC 1750A modules connected by a parallel bus and a system mass memory. The three components are connected by two optical high-speed data busses. The modeling was done while both the hardware and software were under development. The process of developing and validating the models produced a significant V&V payoff for the design teams. Formal modeling forced early consideration of hardware/software, inter-module, and inter-application interfaces that were overlooked during the system design process. This led to forecasting system problems that normally would not have been discovered until system integration. This paper will review the modeling effort and show, in a systems engineering context, how abstract modeling can serve as a powerful method for early discovery of interface errors normally not found until integration. © 1992 The Authors.