Consider an object-oriented model with a class diagram, and a set of object sequence diagrams, each representing the design of object interactions for a use case. This article discusses how such an OO design model can be automatically transformed into a component-based model for the purpose of reusability, maintenance, and more importantly, distributed and independent deployment. We present the design and implementation of a tool that transforms an object-oriented model to a component-based model, which are both formally defined in the rCOS method of model driven design of component-based software, in an interactive, stepwise manner. The transformation is designed using QVT Relations and implemented as part of the rCOS CASE tool. © 2012 Springer-Verlag.