Designers are increasingly using a collaborative approach called Service Design, involving service providers in the design process. This approach differs from traditional client relationships in four ways: it's more dynamic, based on evolving ideas, focuses on innovation processes, and often starts from vague points. Designers face challenges convincing service providers of the importance of this approach, as they are unfamiliar with it and their organizations are not prepared for collaboration. The goal is to develop a participatory design intervention to enhance collaboration between designers and service providers in Service Design processes.