Software Product Lines (SPL), Component Based Software Engineering (CBSE) and Commercial Off The Shelf (COTS) components provide a rich supporting base for creating software architectures. Further, they promise significant improvements in the quality of software configurations that can be composed from pre-built components. Software architectural styles provide a way for achieving a desired coherence for such component-based architectures. This is because the different architectural styles enforce different quality attributes for a system. If the architectural style of an emergent system could be predicted in advance, a System Integrator could make necessary changes to ensure that the quality attributes dictated by the system requirements were satisfied before the actual system was deployed and tested. In this paper we propose a model for predicting architectural styles based on use cases that need to be met by a system configuration. Moreover, our technique can be used to determine stylistic conformance and hence indicate the presence or absence of architectural drift