Increasing complexity due to the multitude of different functions and their interactions as well as a rising number of different product variants are just some of the challenges that must be faced during the development of multi-functional system families. Addressing this trend we present an approach combining model-based development with product line techniques aiming at a consistent description of a software product family as well as supporting the configuration of its variants. We integrate the concept of variability in our framework [7] which only supported the representation of single software systems on subsequent abstraction levels so far. For the configuration of a concrete product we extend this framework by a feature-based model which allows to configure and derive single systems from a system family model. Furthermore, we explain how the complexity due to the possibly huge amount of configuration decisions can be handled by means of a staged configuration process.