Managing variability and reuse of features and requirements for large and complex organizational structures

Feature trees are a well-established instrument for domain analysis and modeling (Czarnecki and Eisenecker, 2000; Kang et al., 1990). But for extremely complex product families like a vehicle manufacturer´s product range, they become very large, and thus cumbersome and inflexible. This is particularly true when changes to the tree´s structure have to be managed and documented over a long period of time. Furthermore, a conflict of aims arises when using feature trees in large organizations: while a single global feature tree for the entire company is desirable, local amendments are indispensable because often some applications of the feature models require amendments not visible in other application contexts. A research project at DaimlerChrysler, being conducted in cooperation with the Technical University of Berlin, has examined this problem in detail and elaborated an approach based on a distribution of the feature tree definition over several hierarchical levels. Using this approach, amendments to the feature structure can be introduced locally at first, and can later become valid in a broader context, if desired. Currently the approach is being evaluated and refined in case studies.