Substantial research has demonstrated the importance of bridging structural holes across functional groups in IT projects. We argue that bridging structural holes is necessary but insufficient for ensuring project success. An additional requirement is that knowledge holes across functional groups need to be bridged to enable effective coordination across functional groups. We propose and empirically study the concept of knowledge holes in a case study of an ERP upgrade. Our preliminary findings suggest that complementary to the concept of structural holes, the concept of knowledge holes is useful for explaining different project outcomes.