Analyzing commonalities and variabilities among products of a product line is an essential activity for product line asset development. A feature-oriented approach to commonality and variability analysis (called feature modeling) has been used extensively for product line engineering. Feature modeling mainly focuses on identifying commonalities and variabilities among products of a product line and organizing them in terms of structural relationships (e.g., aggregation and generalization) and configuration dependencies (e.g., required and excluded). Although the structural relationships and configuration dependencies are essential inputs to product line asset development, they are not sufficient to develop reusable and adaptable product line assets. Other types of dependencies among features also have significant influences on the design of product line assets. In this paper, we extend the feature modeling to analyze feature dependencies that are useful in the design of reusable and ad...