Standard Approach to Identifying and Defining Functions for Systems Development and Safety Assessments
The Safety Assessment Process, defined by SAE ARP 4761, associated regulatory guidance, and the system development process defined by SAE ARP 4754 are built on an understanding of the functions performed by a system or systems. These recommended practices do not provide, or reference, specific guidance regarding function definition, though they do provide some conventional airplane examples. The function is central to the entire development effort, and it is essential that the functions be identified and described such that the development and safety assessment processes can be applied consistently throughout the development program, and beyond. Without a systematic process for establishing and describing functions, the application of the development and safety assessment processes can be complicated by overly inclusive functions and functions applied at the wrong level of abstraction.