The role of features and aspects in software development

Feature-Oriented Programming (FOP) and Aspect-Oriented Programming (AOP) are complementary technologies. Though they aim at crosscutting modularity, they do so in different ways. The author observed that FOP and AOP can be combined to overcome their individual limitations. Consequently, Aspectual Feature Modules (AFMs) are proposed, a representative approach that unifies FOP and AOP. From this symbiosis the novel notion of Aspect Refinement (AR) is derived that integrates aspects into the stepwise development philosophy of FOP. AFMs and AR are used in a non-trivial case study to create a product line of overlay networks. Also a set of guidelines is presented to assist programmers in how and when to use FOP and AOP techniques for implementing product lines in a stepwise and generative manner. Finally, the author answers the question of how FOP and AOP-related implementation techniques are used today by analyzing a representative set of AspectJ programs of different sizes. He observed that aspects are used frequently for implementation problems that are closely related to FOP. It is discussed why this is not surprising.