Adaptive software is a class of software which is able to modify its own internal structure and hence its behavior at runtime in response to changes in its operating environment. Adaptive software development has been an emerging research area of software engineering in the last decade. Many existing approaches use techniques issued from software product lines (SPLs) to develop adaptive software architectures. They propose tools, frameworks or languages to build adaptive software architectures, but do not guide developers on the process of using them. On the other hand, the components replacement at runtime remains a complex task since it must ensure the validity of the new version, in addition to preserving the correct completion of ongoing activities. To cope with these issues, this book proposes an adaptive software development process where tasks, roles, and associate artifacts are explicit. The process aims at specifying the necessary information for building adaptive software architectures. On the other hand, an adaptation mechanism is proposed based on transactions management for ensuring consistent dynamic adaptation.