This paper summarizes our experience with introducing feature modelling into several product lines within Siemens. Feature models are used for solving various tasks in the product line lifecycle, starting with scoping the reusable asset base up to support for actual product configuration. Using feature models as primary artefacts for managing variability early in the lifecycle, we could improve the efficiency and transparency of scoping activities considerably and made the development efforts way easier to schedule. On the other end of the lifecycle, feature models lowered the engineering efforts in solution business in supporting product configuration and instantiation.