Synthesis and evaluation of engineering processes for the development of airborne electronic equipment

Abstract

Electronic equipment installed on aircraft has to meet with airworthiness requirements and standards. Airworthiness, i.e. confidence that the equipment is suitable for its intended functions and safe to operate, is established by scrutiny and the meticulous control of the data associated with the system design and associated engineering processes, manufacturing and installation processes, operating instructions and procedures, and the maintenance aspects of the equipment. All deviations, including upgrades and modifications to any of these aspects, are subjected to prudent controls. A "paper trail" of technical decisions, implementation details, validation and verification results and evidence of adequate control of these must be established and maintained throughout the operational life of the equipment for each operational version of the affected systems. In particular, equipment containing embedded software is generally highly complex, making this effort of managing the airworthiness related information a demanding undertaking. A significant number of sources, e.g. aerospace industry recommended practises, system and software engineering standards, and other relevant publications, contribute to the set of references against which airworthy products are developed. The information contained in these sources is of a generalised nature and typically represents particular points of view, depending on the source. The formulated problem was therefore to derive a process description specific to the development of airborne electronic equipment, which complies with this collection of requirements efficiently by detailing a comprehensive and consolidated methodology. In order to provide a scientific grounding for the study, techniques associated with the methodology of Design Science Research (DSR) were applied. The general principle of DSR is that an innovative, purposeful artefact is created for a specified and adequately formulated problem domain and a mechanism to provide a solution is proposed. The artefact, which represents the aforementioned solution, must be systematically evaluated and the result must be integrated in practise. Most accumulated scientific knowledge can be classified as descriptive knowledge, which contains descriptions of phenomena and interrelationships between phenomena. DSR is a method for establishing prescriptive knowledge, which entails constructs, models, methods, instantiations and design theories. This study is concerned with knowledge of a method that meets with the definition of prescriptive knowledge. The artefact, within the context of the DSR method, is a definition of a unified process for the development of airborne electronic equipment. This description identifies the necessary and sufficient set of activities required to develop and support such a system and the accompanying documentation efficiently, within the specific constraints applicable to Denel Aviation. This process description is based on applicable aerospace industry recommended practises and other prevalent systems engineering references, as well as on practical experience in the development of such systems. In particular, experience from the development of an automatic flight control system for an attack helicopter, and the integration of a modern navigation system on a medium transport helicopter, were applied in the formulation of this process description. The process description is implemented by Denel Aviation as a company standard for the development and airworthiness assurance of airborne electronic equipment, and is used for the detailed planning of new projects. The process of formally approving the process description for use by Denel Aviation served to validate the outcome of the study in terms of DSR principles