Existing studies of supplier involvement in new product development have mainly focused on project-related short-term processes and success factors. This study validates and extends an existing exploratory framework, which comprises both long-term strategic processes and short-term operational processes that are related to supplier involvement. The empirical validation is based on a multiple-case study of supplier collaborations at a manufacturer in the copier and printer industry. The analysis of eight cases of supplier involvement reveals that the results of supplier–manufacturer collaborations and the associated issues and problems can best be explained by the patterns in the extent to which the manufacturer manages supplier involvement ...