The service-oriented approach has become more and more popular, now allowing highly integrated and yet heterogeneous applications. Web services are the natural evolution of conventional middleware technologies to support Web-based and enterprise-level integration. The highly dynamic characteristics of service-oriented applications means their validation is a continuous process that often runs in parallel with execution. It is not possible to clearly distinguish between the predeployment validation of a system and its use, nor is it possible to guarantee that the checks passed at a certain time will be passed at a later time and in the actual execution environment as well. Baresi and Di Nitto have put together the first reference on all aspects of testing and validating service-oriented architectures, taking into account these inherent intricacies. The contributions by leading academic and industrial research groups are structured into four parts on: static analysis to acquire insight into how the system is supposed to work; testing techniques to sample its actual behavior; monitoring to probe its operational performance; and nonfunctional requirements like reliability and trust. This monograph is an initial source of knowledge for researchers in both academia and industry in the field of service-oriented architecture validation and verification approaches. They will find a comprehensive survey of state-of-the-art approaches as well as techniques and tools to improve the quality of service-oriented applications.