The aim of the study is to look at the impact of 'NPD process planning proficiency' on NPDperformance. In particular, the current study examines this effect at firm's level (NPD program), rather than atthe level of individual project. This study investigate the impact of process planning proficiency consideringother NPD proficiencies (i.e. marketing and technical proficiency). In addition to the main effect of processplanning proficiency, the current study investigates the interaction effect between process planning proficiencyand marketing proficiency (or technical proficiency). Based on a cross-industry sample of 103 Koreanmanufacturers, this study examines the impact of NPD process planning proficiency on product familyperformance. The current study focuses on platform projects which play a critical role on product family'ssuccesses. NPD process planning proficiency has significant impact on both NPD technical and commercialperformance. Technical proficiency is not directly associated with NPD performance. However, this study findsthe interaction effects of technical proficiency with process planning proficiency on NPD performance. (ÀÌÇÏ »ý·«)