Towards Seamless Integration of N-Version Programming in Model-Based Design

The ever-growing complexity of present-day soft- ware systems raises new and more stringent requirements on their availability, pushing designers to make use of sophisticated fault tolerance techniques far beyond the areas they were traditionally conceived for, and bringing new challenges to both the modelling and implementation phases. In this paper, we propose a design pattern to model in a domain-specific language one of the prominent fault-tolerant techniques, namely the N-version programming. It can be integrated seamlessly into existing applications to enhance their functional correctness, while still preserving the timing characteristics, in particular the sampling times. Besides, it is also designed in a way to ease the automatic code generation. A counterpart of the same framework is also implemented in a lower-level programming language, for use when direct model execution is impractical, like in severely resource-limited embedded targets.