XaaS is a collective term said to stand for a number of things including "X as a service,". Everything (and anything!) as a service is a rapidly expanding model not only in Cloud service but also in every other industry. It grew from utility service model and applied to IT and now non-IT services as well. This is the new delivery models and shall warrant new approach to service management. But before that it will require a new approach to design and publish a service. Like service management architecture that we discussed in our earlier publication, service architecture is largely an ignored aspect in service design. IT professionals talk more about application architecture than the service architecture. This book discusses the sets of service properties that collectively form a service architecture and then also talks about the building blocks of XaaS service management system.