Sustainability and Performance Evaluation in Third Sector Partnerships: The Case of Turin Fast Track City

COVID-19 radically changed how public services (activities of general interest) are pursued and administered. The search for resilient models has prompted public administration to test new regulatory approaches and to involve the third sector in the provision of primary services. This study investigates the sustainability and capacity of these models, specifically the implementation of a co-planning and co-design model aimed at measuring the possible creation of value and achieving common objectives. On the basis of an analysis of the development of the Turin Fast Track City project, the study employs a longitudinal method to identify not only the sustainability of the model but also new effective performance measurement tools, such as SIA analysis and integrated social accounting using financial and non-financial elements. The study also highlights critical elements aimed at supporting future investigations.