Cascaded refactoring for framework

Refactoring of source code has been studied as a preliminary step in the evolution of object-oriented software. We extend the concept of refactoring to the whole range of models used to describe a framework in our methodology: feature model, use case model, architecture, design, and code. We view framework evolution as a two-step process: refactoring and extension. The refactoring step is a set of refactorings, one for each model, that cascades through them. The refactorings chosen for a model become the rationale or constraints for the choice of refactorings of the next model. The cascading of refactorings is aided by the alignment of the models. Alignment is a traceable mapping between models that preserves the commonality-variability aspects of the models.