This book invites the reader on a journey of discovery of service systems. From a Service-Dominant-Logic perspective, such systems are the building blocks of all economic activity, and innovation of new service systems holds the promise of a new industrial revolution. Users navigating web sites, customers interacting with intelligent mobile retail applications, patients interpreting advice from health-care professionals and other sources, students interacting with teachers and learning materials, city dwellers invoking smart service applications for transportation routing, and the unlimited variations of smart service systems that will be enabled by the Internet of Things and other technologies provide ample evidence of the need for service innovation. This book presents an overview of the foundational constructs of service science and models of co-creative systems, with the aim of enabling the reader to be a service innovator. The value proposition of this book is the opportunity to fill each reader's knowledge gaps and offer a comprehensive, coherent, and introductory overview of service system modeling.