This dataset was created as part of a PhD project that investigated the institutionalization of planning support systems in Rwandan spatial planning processes. It contains anonymized interview transcripts and a data codebook used in the research to investigate the role of the drift concept in embedding planning support systems within Rwandan spatial planning processes. The data were collected from January to March 2020 during fieldwork and internship in Rwanda. The dataset includes an internship report. It also contains published supplementary materials on the overview of secondary data, primary data collection, data coding (themes and codes), and results. Data coding was done using the ATLAS.ti Version 8.4.24. Thematic analysis adopted the deductive and inductive coding methods.