This paper examines how firms succeed to leverage supplier involvement in product development. The paper extends earlier work on managing supplier involvement by providing an integrated analysis of results, processes and conditions both at the level of individual development projects and the overall firm. Following a multiple-case study approach with theoretical sampling, the study is carried out by examining eight projects in which four manufacturers from different industries involve multiple suppliers. The findings suggest that successful supplier involvement is dependent on the coordinated design, execution and evaluation of strategic, long-term processes and operational, short-term management processes and the presence of enabling facto...