Features are essential characteristic of applications within a product line. Features organized in different kinds of diagrams containing hierarchies of feature trees are closely related to variation points, which appear at different levels and life cycle phases for product lines. Optional and alternative variants attached to variation points may by additional constrained by mutual-exclusion or –inclusion and classified by binding modes, times and sites. Variability leads further to crosscutting variability. Reducing an n:m-relation between feature and variation point would help organizing scalable and traceable software models according to SoC with less intertwined feature trees. Keywords : feature composition, feature interaction, crosscutting features, product lines Workshop Goals: identify and categorize characterizing properties of various instances of feature interaction problems Working Groups: feature-based methods for product lines, integrating UML with featurebased methods...