An Introduction to Software Product Line Refactoring

Although software product lines (PLs) can bring significant productivity and quality improvements through strategic reuse, boot-strapping existing products into a PL, and extending a PL with more products, is often risky and expensive. These kinds of PL derivation and evolution might require substantial effort and can easily affect the behavior of existing products. To reduce these problems, we propose a notion of product line refactoring and associated transformation templates that should be part of a PL refactoring catalogue. We discuss how the notion guides and improves safety of the PL derivation and evolution processes; the transformation templates, particularly when automated, reduce the effort needed to perform these processes.