Automated validation of minimum risk model-based system designs of complex avionics systems

Abstract

Today, large civil aircraft incorporate a vast array of complex and coupled subsystems with thousands of electronic control units and software with millions of lines of code. Aircraft suppliers are challenged to provide superior products that are developed at a minimum time and cost, with maximum safety and security. No single person can understand the complex interactions of such a system of systems. Finding an optimal solution from large sets of different possible designs is an impossible task if done manually. Thus, written, non-executable specifications carry a high degree of product uncertainty. As a result, more than two-thirds of all specifications need to be reworked. Since most specification flaws are discovered and resolved at a late stage during development, when expenditures for redesign are at a maximum, the development approach currently used has a high probability of project cost and time overruns or even project failure, thus maximizing the risk of development. It is the aim of this work, to develop a model- and simulation-based systems engineering method with associated design and validation environment that minimizes the risk of development for complex systems, e.g. aircraft. The development risk is a minimum, if all development decisions are validated early against the services of a product at mission level by the final customer. To do so, executable specifications are created during design and validated against the requirements of system services at mission level. Validated executable specifications are used and updated for all decisions from concept development through implementation and training. In addition, virtual prototypes are developed. A virtual prototype is an executable system specification that is combined with human machine interface concept models to include usability requirements in the overall design and to enable interactive specification validation and early end user training by means of interactive user-driven system simulation. In a first step, so called executable workflows and simulation sets are developed to enable the execution of sets of structured and coupled simulation models. In a second step, a model- and simulation-based development and validation process model is developed from concept design to specification development. In a final step, two different validation processes are developed. An automated validation process based on executable specifications and an interactive validation process based on virtual prototypes. For the development of executable specifications and virtual prototypes, plug-and-play capable model components are developed. The developed method is validated for examples from civil aircraft development with focus on avionics and highly configurable and customizable cabin systems.