This paper explores a designerly approach to open innovation initiation as start of the PhD research of the third author. More specifically, it presents the application of co-reflection sessions by designers in a healthcare open innovation project to initiate multi-stakeholder participation. Integrating co-reflection in open innovation initiation provides designers with the opportunity to a) negotiate with and function in multi-disciplinary environments consisting of stakeholder representatives and stakeholder customers (possible end-users); b) analyze complexity and structure of stakeholder ambitions, wishes, concerns and restrictions in order to frame a collaboration space; c) synthesize, visualize and materialize the value proposition to communicate the benefits to multi-stakeholder networks in order to define a design space and motivate their participation; and what is more important, keeping the balance between design thinking and design action. Lessons learned from this study a) can be used to provide a set of skills and practical guidance to designers when initiating open innovation b) define a spectrum for research on how designers can initiate innovation
