Open, collaborative, and participative practices trigger complex change processes that lead to societal impact. Together with a diverse set of stakeholders, we set out to make these different pathways to impact visible, explicit, and tangible. The co-creatively developed OIS Impact Model shows how Open Innovation in Science (OIS) initiatives for involvement and engagement should be designed and what effects they could have on personal awareness and competencies, behavior and life circumstances of all those involved. This document describes the process of how the OIS Impact model was co-creatively developed. The model can be found here: https://doi.org/10.5281/zenodo.10078636