Software and Systems Product Line (SSPL) engineering has shown capabilities to reduce costs and time to market. This is thanks to the creation and management of a common platform dedicated to develop a family of products. These latters can be a family of mobile phones, a family of different brake systems variants for automative needs, etc. Recently, more and more large-scale companies start to implement SSPL engineering in their domains by adopting Model-Based Systems Engineering (MBSE). Systems Product Line (PL) engineering is much broader than software PL engineering. Therefore, various aspects of variability (e.g. functional and quality attributes variabilities) have to be considered in MBSE. However, variability integrated in MBSE is still limited to functional variability. This paper contributes to enhance the SSPL modelling based on SysML by extending the SysML language. The principle aim is to include various aspects of variability. In fact, a holistic variability model is proposed to define the SysML extensions by means of the UML profiling mechanism. This permits to express variability constructs in different SysML modelling artifacts. We also present an application example namely the brake systems family extracted from Splot repository. We in fact, show how our SysML extensions are concretely used.