This SpringerBrief explores the internal workings of service systems. The authors propose a lightweight semantic model for an effective representation to capture the essence of service systems. Key topics include modeling frameworks, service descriptions and linked data, creating service instances, tool support, and applications in enterprises. Previous books on service system modeling and various streams of scientific developments used an external perspective to describe how systems can be integrated. This brief introduces the concept of white-box service system modeling as an approach to model the internal aspects and elements of service systems. This approach provides descriptions that can be used for service management, optimization, and analytics. Service Systems: Concepts, Modeling, and Programming is designed for researchers, teachers, and advanced-level students who want to learn about the new emerging field of service science and IS/IT practitioners who are looking for better ways to describe, model, and communicate services.