Although product family design methods are well established, little research has focused on Product-Service-System (PSS) family design. A PSS family design method is proposed in this paper that parallels methodology for designing product families. Separate platforms are proposed for products and for services. However, couplings between product and service platforms are identified and incorporated into the design method. Design problem formulations are proposed for PSS family platforms and for the PSS family itself, using a module-based approach, in contrast to a platform scaling approach. Alternative methods are investigated and compared for solving these problems. The application domain of Assistive Mobility (AM) is identified as a promising PSS family in this work. If smart technologies are integrated into AM devices, such as manual wheelchairs, powered wheelchairs, walkers, and rollators, then patient diagnosis and treatment, as well as device maintenance, services are enabled with these smart technologies, demonstrating that smart AM devices are a promising PSS family.
