Improving Product Line Architecture Design and Customization by Raising the Level of Variability Modeling

Abstract

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 usually perceive architecture variability from the perspective of variant features or variant design decisions that are mapped into groups of architecture variation elements. In the paper, we describe heuristics to identify configurations of variation elements that typically form such groups. We call them variation constructs. We developed an architecture variability management method and a tool that allow developers to work at the variation construct level rather than at the level of individual variation elements. We have applied and evaluated the proposed method in the development and maintenance of a medium-size financial product line. Our experience indicates that by raising variability modeling from variation element to construct level, architecture design and customizations become more intuitive. Not only does our method reduce the design and customization effort, but also better ensures consistent configuration of architectural variation elements, avoiding errors.