The aim of this research is to improve our understanding of the success factors of the front end of innovation (hereinafter, front end) for highly innovative products. Our approach is uncommon in three ways. First, the front end is not considered as a uniform whole, but as consisting of three heterogeneous phases/outcomes, which could require a different mix of resources. Second, a comprehensive range of explanatory factors is scrutinized, including company-, people- and openness-related factors. Third, openness is represented not only by relational breadth and depth, but also relational quality. We examine information originating from two different sources: (1) an ad-hoc survey which provided information from a representative sample of 190 companies, and (2) a secondary data source compiled by the Statistical Office of a regional government in Spain. By using two information sources, we were able to triangulate data and control for validity and common method bias. We found that success in each of the three phases of the front end of new product development is explained by different factors. Relational quality, strategic flexibility and creative culture contribute to the creativity of ideas. The drivers of product definition proficiency appear to be relational quality, technical expertise and creative culture. Finally, front end and technical expertise, leadership and relational depth contribute to project plan proficiency. Overall, our research suggests that empirical studies that consider the front end as a whole and do not consider openness, and, in particular, relational quality, could be misleading.