Over recent years, the literature on eco-innovation has expanded considerably. Scholars concur that eco-innovation is intricate, necessitating diverse external expertise. Collaboration with and access to external knowledge sources enable companies to surmount internal limitations, thereby achieving competitive advantages. Within this framework, the concept of Open Eco-Innovation (OEI), which integrates open innovation with eco-innovation, has garnered attention. Nevertheless, the factors influencing OEI projects' success remain underexplored. This study examines these factors through four Open Eco-Innovation projects in the outdoor sports industry and 28 interviews with key project members. The case studies underscore the prominence of OI-related levers, primarily the strategic and relational alignment of partners. However, to ensure sufficient alignment, other levers must pre-exist, establishing a sequence in the activation of these levers. While regulatory pressures and industry threats initially drive the process, encouraging firms to develop EI projects internally, attaining a certain maturity in EI terms subsequently facilitates the strategic and relational alignment of partners in OEI projects
