The Transactions on Pattern Languages of Programming subline aims to publish papers on patterns and pattern languages as applied to software design, development, and use, throughout all phases of the software life cycle, from requirements and design to implementation, maintenance and evolution. The primary focus of this LNCS Transactions subline is on patterns, pattern collections, and pattern languages themselves. The journal also includes reviews, survey articles, criticisms of patterns and pattern languages, as well as other research on patterns and pattern languages. This book, the fifth volume in the Transactions on Pattern Languages of Programming series, includes papers on patterns and pattern languages for engineering specific kinds of application and for improving processes, as well as papers on the discovery, validation, and systemic use of patterns more broadly.