Support for variability in use case modeling with refinement

The development of software product lines with model-driven approaches involves dealing with diverse modeling artifacts such as use case diagrams, component diagrams, class diagrams, activity diagrams, sequence diagrams and others. In this paper we focus on use cases for product line development and we analyze them from the perspective of variability. In that context we explore the UML (Unified Modeling Language) «extend» relationship. We also explore the functional refinement of use cases with «extend» relationships between them. This work allows understanding the activities of use case modeling with support for variability and of use case modeling with functional refinement when variability is present.