Evolution in Software Product Lines

Product-line architectures, i.e. a software architecture and component set shared by a family of products, represents a promising approach to achieving reuse of software. Several companies are initiating or have recently adopted a product-line architecture. However, little experience is available with respect to the evolution of the products, the software components and the software architecture. Due to the higher level of interdependency between the various software assets, software evolution is a more complex process. In this paper, we discuss the results of a case study concentrating on the evolution of software assets in two swedish organizations that have employed the product-line architecture approach for several years. We have identified categorizations of the evolution of the requirements, the software architecture and the software components and analyze the relations between the categories. Based on this model, we present a set of guidelines that support the evolution of software assets in a product-line.