This discusses the shift of design focus looking at innovation history, and points out the importance of research on designing a service system. The focus of innovation is shifting from seeds or needs oriented products to a service system creating values by the interactions of providers and receivers, and to open innovation. At the same time, the scope of design becomes wider including the whole system design. Because of these shifts, the new research on service system design is emerging. In this paper, a framework based on two viewpoints, such as systems with value sharing condition and scopes of system layers are proposed identifying technical and social difficulties of designing a service system.