Interactive service robots obtain instructions or data from human users and provide information or act to assist us in everyday tasks. For example, few such systems guide visitors through exhibitions or malls helping to educate and advertise. However, so far none of the existing systems has become an off-the-shelf product. The main challenge for such highly complex systems to achieve market breakthrough is their design using cutting-edge technology under marketing and acceptance aspects. This book presents the successful combination of two system-design approaches to meet this challenge: the V-Model, a system engineering method to structure the design to fulfill technical and commercial requirements; and the Analytic Hierarchy Process (AHP), a decision making approach based on weighted criteria to support design decisions at various system levels. The implementation of this combined system design approach is demonstrated on the development of interactive robots that now guide customers to products in home improvement stores. The general applicability is verified by the successful transfer of this approach to the design of an interactive home-care robot system.