Agile Software Architecture Chapter 3. Refactoring Software Architectures

This chapter describes how to systematically prevent software architecture erosion by applying refactoring techniques. Software architecture modifications are common rather than the exception in software development. Modifications come in different flavors, such as redefining or adding requirements, changing infrastructure and technology, or causing changes by bugs and incorrect decisions. But no matter where these changes originate, they need special attention from software architects. Otherwise, if software architects merely focus on adding new features—(changes or extensions that by themselves might not be adequate), design erosion will be the final result. In a systematic approach, software architects evaluate the existing software design before adding new artifacts or changing existing ones. Whenever they identify architecture problems, they immediately resolve architectural issues, thus assuring high quality and sustainability. Software architecture refactoring enables such iterative architecture improvement. It consists of indentifying problems, applying the right refactorings, and testing the results. Architecture refactoring is often combined with code refactoring activities to add the best value. Refactoring patterns offer proven solutions for recurring architectural problems, hence providing a toolset to software engineers.