The concept of a software product line is a promising approach for increasing planned reusability in industry. For planning future requirements, the integration of domain analysis activities with software development for reusability turned out to be necessary, both from a process and from an economic point of view. In this context, variability of requirements in a domain is expressed by feature models. Feature models enable planning and strategic decisions both for architectural and for component development. By expressing feature dependencies, feature models are used to partition the architecture and the implementation. For industrial use, appropriate methods for modeling variability in requirements, design and implementation as well as tools for supporting feature models and for integrating them with other models are needed. The ECOOP workshop explored the possibilities and limitations of feature models and supporting methods. Its fully reviewed contributions aim at improving the fea...