2.2.1 When is Enough Enough? Tailoring Processes in Systems Engineering

Abstract

AbstractSystems Engineering Processes are usually written to be applied to the development of a complex system, starting from a blank sheet of paper. The mindset is that the processes have to be followed with 100% compliance to even stand a chance of developing a successful system.In practice, many System Engineering activities involve the development of small, less complex systems, often by modification of a pre‐existing system. Even large, complex systems will be subject to incremental or spiral development where the increments are deliberately chosen to avoid complex interactions with the rest of the system. In addition, the full suite of systems engineering practices are designed to address all types of risks but not all projects will need such techniques. For example, stakeholder analysis and requirements elicitation will not be critical if the system is undergoing a refresh to address component obsolescence. One size fits all is a wasteful approach when you consider the processes are designed for all possible systems.Under these circumstances, is it appropriate to apply the full weight of the Systems Engineering processes used for the initial development of a complex system to these incremental developments or to less complex systems? If not, what parts of the process should be simplified or omitted, and why?It is said that “Processes are guidance for wise people” ‐ but if you don't follow the process, are you wise or otherwise? The focus of this paper is to present a “wise” approach to selecting which processes to follow, and to what level of rigor. It describes an approach grounded in Technical Risk Management and Probability Calculus to decide how to tailor Systems Engineering processes when developing less complex systems or introducing incremental developments or modifications to a complex system.