MBD & code generation: A cost-effective way to speed up HMI certification

Abstract

This paper compares the traditional Text-Based approach with Model-Based Design (MBD) approach and demonstrates the efficiency of adopting Model-Based Design when coupled with application simulation and automatic code generation. Organizations can see gains not only in the reduction of the development cycle but also in the overall improvement of the DO-178B or DO-178C certification process; including reduction of schedule and costs, and improvements in the quality and reliability. In the old school of thought, the methodology relies on textual specifications and physical prototypes. That is why the Text-Based Design approach is tightly associated with the waterfall methodology where all the textual requirements are manually coded, inspected, and tested on a real embedded system. In this method, changes in any part of the waterfall chain are very costly and time consuming, leaving almost no room to iterate on the design. By contrast, in the Model-Based Design approach, the specifications are self contained in the HMI Model. The HMI requirements are defined in an unambiguous way and often captured in a formal definition language. The model owns many graphical representations, called model views, such as Structure Diagram, State Charts, Interaction and Sequence diagrams, etc. Model-Based Design incorporates the behavior and performance requirements to properly describe the overall avionics application. This model possesses graphical representations and can be used throughout the entire development cycle, from the requirement inception phase up to the final embedded application deployment. Model-Based Design offers a collaborative approach to avionics development and allows engineers to inexpensively experiment with various concepts by involving hardware as late as possible in the development process. Correcting problems in the early simulation phase is undeniably the strongest argument in favor of the Model-Based Design approach for developing certifiable or non-certifiable avionics applications.