In this paper we report from a case study on OSS adoption conducted in a large multinational organization in the secondary software sector. Our study contributes to theory and practice of project management for OSS adoption, with important implications for different stakeholder groups and internal method usage. In particular, our results concern the following three issues in relation to a wish to increase the usage of OSS within the organization. Firstly, from a management level perspective, we elaborate on knowledge transfer and suggest a number of recommendations. Secondly, from an operational level perspective, we elaborate on potential benefits from changed work practices. Thirdly, from our analysis of the relationship between the project management model and the maintenance management model, we suggest adaptations to existing work practices by highlighting the importance of considering maintenance costs early in a project.