A Product Line Architecture Variability Design Methodology

Product Line Architecture (PLA) plays a central role in software product line development. In order to support architecture-level variability modeling, most architecture description languages (ADLs) introduce architectural variation elements, such as optional component, connector and interface, which must be customized during product derivation. Variation elements are many, and design and customization of PLA at the level of individual variation elements are difficult and error-prone. We observed that developers perceive architecture variability at higher level, in the context variant features or variant design decisions that usually are mapped into groups of architecture variation elements. In the paper, we describe heuristics to identify certain types of such groups which we call variation constructs. It is easier for developers to work at the variation construct level rather than at the level of individual variation elements. We also proposed a method on how to map feature to construct and a method on how to implement all kinds of constructs. Based on the variation construct concept, we developed an architecture variability management method, and a tool that implements the method. We have successfully applied the proposed method in the development and maintenance of a medium-size financial product line. Our experience indicates that by raising the level of variability modeling not only do we reduce the design and customization effort, but also better ensure consistent configuration of architectural variation elements.