This data is for Chapter 4, part of the PhD research that investigated the institutionalization of planning support systems (PSS) in Rwandan spatial planning processes. The chapter investigates how organizations and their institutions serve as distinct mechanisms that influence the institutionalization of PSS within spatial planning practices. The long-term use of the Spatial Development Framework (SDF-PSS) methodology in Rwanda, as a case, explores how institutions and organizations enable or constrain the integration of PSS into planning processes. Grounded in Structuration theory and the duality of structure and technology, the research analyzes the reciprocal relationship between technology, human action, and institutional mechanisms. The primary data consist of semi-structured interviews with twenty-four (24) respondents selected by purposeful sampling and the snowballing method to represent the categories of research respondents. In compliance with the obtained interview consents and ethical considerations in the research, the data are archived with participant anonymity maintained.