‘Healthy Kids of Seinäjoki’ is the City of Seinäjoki’s operating model for promoting the wellbeing of children, young people and families. The operating model includes the city’s own industries, residents, organisations and associations, educational and research organisations and private-sector companies. Through cooperation with these actors, the aim here is to build lasting change in the lives of children, young people and families. ‘Healthy Kids of Seinäjoki’ brings together the necessary actors and makes visible all of the good work that is being done in the city to promote the wellbeing of families. The aim of MDI’s work was to support the Healthy Kids of Seinäjoki organisation in modelling the development platform and to structure ideas and different implementation methods for implementing the development platform. The development platform aims to enable the development and implementation of user-oriented services and products. The work included interviews, a workshop for stakeholder representatives and modeling the development platform.