A theoretical foundation of variability in component-based development

Component-Based Development (CBD) is revolutionizing the process of building applications by assembling pre-built reusable components. Components should be designed more for inter-organizational reuse, rather than intra-organization reuse through domain analysis which captures the commonality of the target domain. Moreover, the minor variations within the commonality should also be modeled and reflected in the design of components so that family members can effectively customize the components for their own purpose. To carry out domain analysis effectively and design widely reusable components, precise definitions of variability-related terms and a classification of variability types must be made. In this paper, we identify the fundamental difference between conventional variability and component variability, and present five types of variability and three kinds of variability scopes. Each type of variability is precisely defined for its applicable situations and guidelines. Having a formal view on variability, not only the domain analysis but also component customization can be effectively carried out in a precise manner. q 2004 Elsevier B.V. All rights reserved.