Project tailoring is discussed in academia and industry as a way to bridge the project-specific adaptation of generic organizational reference process models. Research into process tailoring in interdisciplinary product development is currently limited. We have developed a structure-based approach for supporting process tailoring, addressing limitations in existing approaches through: Concrete method support; systematic analysis of documented tailoring knowledge using structural analysis; and social aspects, e.g. stakeholder inclusion. The approach has been evaluated in eight case studies.