Traditional design representations are inadequate for generalized reasoning about modularity in design and its technical and economic implications. We have developed an architectural modeling and analysis approach, and automated tool support, for improved reasoning in these terms. However, the complexity of constraint satisfaction limited the size of models that we could analyze. The contribution of this paper is a more scalable approach. We exploit the dominance relations in our models to guide a divide-andconquer algorithm, which we have implemented it in our Simon tool. We evaluate its performance in case studies. The approach reduced the time needed to analyze small but representative models from hours to seconds. This work appears to make our modeling and analysis approach practical for research on the evolvability and economic properties of software design architectures.