The four dimensions of Variability and their impact on MBPLE: How to approach variability in the development of aircraft product lines at Airbus

The development of complex systems such as aircraft product lines requires the support of advanced modeling methodologies such as Model-Based Systems Engineering (MBSE) and Product-Line Engineering (PLE). To enable the development of such complex product lines, Airbus is adopting the combination of MBSE and PLE, a method previously applied in other industries and known as Model-Based Product Line Engineering (MBPLE). In adopting MBPLE it is necessary to understand the type of constraints that influences the definition of variability within a development program or project. This paper proposes four different dimensions of variability which facilitate and guide the application of MBPLE at Airbus but that can also be extended to other industries and organizations. Those four dimensions, namely Co-Variability in product, manufacturing and services, Variability in development lifecycle, Variability in layers of abstraction, and Variability in system hierarchy levels, are first described. Afterward, their impact on the MBPLE method steps, namely “Define Product Line Feature Models”, “Define Product Line Assets”, “Select Member Product Feature Configuration” and “Derive Member Product Assets”, is analyzed with the support of an Airbus example.