The document discusses challenges and limitations with existing tools for refactoring code clones. It proposes a new approach to improve clone refactoring that involves three main phases: 1) Control structure matching to identify refactorable clones that have identical control flow. 2) PDG mapping to find the optimal mapping between clone statements that maximizes matches and minimizes differences. 3) Precondition examination to ensure refactoring preserves program behavior. The goal is to parameterize more types of differences, find optimal matches, and add behavior preservation checks. This would allow safer and more effective refactoring of clones.