In recent years, service innovation has become an interesting issue in the service sector. This study investigates many service innovation methodologies in the service sector. However, these service innovation methodologies have some specific restrictions and disadvantages. This study tries to devise a generic service innovation methodology via analyzing how companies conduct service innovation processes. It reviews the past literature to find the common process stages and help develop generic service innovation methodology. It also adopts document analysis and semi-structure in-depth interview to verify the proposed methodology. The findings reveal that the generic service innovation methodology could provide a basis for industrial practice to facilitate new service development with less restrictions and easier adoption.