Building a Software Requirements Specification and Design for an Avionics System: An Experience Report

As with many of the products and systems that pervade us, aircraft rely more and more on software for controlling the behaviour of their systems. In consequence, the field has seen increased work around more up-to-date, effective software engineering technologies for aiding avionics software providers in reducing software and development complexities and supporting them in their certification endeavours. However, there is a lack in the literature of reusable, comprehensive references about avionics software developments in conformance with DO-178C. Moreover, there is a need for a benchmark specification to support the evaluation of proposed engineering approaches in the field. This paper presents a software development case study of an avionics control software for a landing gear system. All the documentation for the software's requirements specification and design has been developed to conform with the DO-178C guideline and the applicable DO-331 and DO-332 supplements for model-based and object-oriented development, respectively. A requirements specification and design methodology is proposed and followed for the construction of the software in the case study. Furthermore, the paper discusses the observations, and challenges and issues experienced throughout the process.