Abstract
Although architecture-centric maintenance and evolution is useful for adjusting software structure and behaviour at higher abstractions, this approach lacks the potential for systematic change reuse. The Pat-Evol project focuses on managing a constructive architecture-based evolution process for service software. It enables continuous automated identification of evolution patterns from the architecture change log with support for pattern specification and instantiation provided by a pattern library. A pattern library acts as a repository to enable pattern-driven change execution, supporting the notion of an off-the-shelf architecture evolution.