Systems engineering enables the successful realization of systems, focusing on defining customer needs early in the development cycle. However there is a lack of methodological support when the development of systems needs to rely on legacy system designs. Furthermore, in the automotive domain, product diversity increases system complexity so much, that reuse becomes much more difficult and time con- suming than usually. We believe a specific strategy must be adopted to prepare for reuse and to achieve systems engineering by reuse. While product line derivation provides the means to obtain single products form a collection of assets, there is still little support for integration with systems engineering practices. In this paper we present an approach which takes into account systems engineering methodolog- ical aspects in product line engineering by rendering the derivation process more flexible. We present the implementation of the tool support for our approach based on the Papyrus1 SysML modeller and exemplify the concepts through a derivation example of the electric parking brake system.