Abstract
Model-driven engineering, an emerging trend in software engineering, has enabled the application of refactoring to UML models. Due to its growing popularity in the domain of refactoring, a number of approaches to specify models and transformation rules have been proposed in literature. A comparison framework is required by researchers and practitioners to guide them in selecting an appropriate approach suitable to their specific needs and trade-offs. In this paper, we provide a set of suitable criteria to evaluate and compare the various model refactoring approaches that can aid practitioners and researchers in the selection process. The paper also compares the refactoring approaches against the framework.