This paper presents the case research methodology developed and adapted while conducting several in-depth process case studies of multi-organizational R&D projects, each of which involved a triad consisting of a diverse set of organizations. This research adapted and improvised upon existing organizational level case research methodologies, while applying them to the multi-organizational project context The paper covers the research objective, the definitions used, the research questions, the choice of the case study methodology, selection of cases, the process of data collection, and the process of case development and analysis including the improvisations made on existing case research methodology. However, the basic theoretical and contextual rationale for undertaking this research, and its results, are outside the scope of this paper. Teaching cases with decision problems in interesting and new multi-organizational contexts are currently being developed from the research cases developed in this study.