This paper presents the cascaded refactoring methodology, which addresses three issues in the existing framework development approaches: identification and realization of variability, framework evolution, and framework documentation. The methodology views framework development as framework evolution, which consists of framework refactoring followed by framework extension. A framework is specified by a set of models. The overall refactoring of a framework is a set of refactorings performed sequentially on the models. Alignment maps are defined to maintain the traceability amongst the models. The constraints of refactorings on a model are derived from the refactorings performed on a previous model. A document template is proposed to document the framework refactoring. The methodology is illustrated by a case study.