Abstract
A graphical approach to modelling engineering design processes is presented, drawing on Pughs Total Design model, the V-Process Model of software and systems engineering and Role Activity Diagrams. The proposed notation combines and extends these representations in a novel way. The concurrent, multi- disciplinary characteristic of Pughs model is retained and extended to embrace concurrent development of subsystems by supplier processes. The V-Process model is adapted to be consistent with Pughs model and both are interpreted as Role Activity Diagrams, enabling the assignment of activity to logical organisational processes, which interact with each other. The resulting notation supports the description of multi-disciplinary processes in-the-large, providing an understandable conceptual model of an organisations total design activity in the development of complex products. It also supports the description of processes and interactions at a detailed level, in a way which is consistent with the high level models. The proposed approach has been trialled on the engineering processes involved in the design and safety assessment of aero-engines and their control systems. Results are discussed and the approach assessed.