The chapter reports on the case study project of the Engineering, Procurement, and Construction (EPC) of a wind park farm in Brazil from the supplier perspective of Siemens Ltd. In the case study, researchers, together with practitioners, further developed project stakeholder analysis by explicitly integrating Sustainable Development (SD) principles. The chapter offers an operative approach and describes the working form systemic board to better handle the increasing dynamics and complexity in contemporary projects and contexts. For project stakeholder management, the consideration of SD principles means in particular: applying a more comprehensive stakeholder management approach with underpinning values that support sustainable development; integrating economic, ecologic, and social interests of project stakeholders into the project objectives to create shared benefit for the project investor and other project stakeholders; broadening the time perspective to consider not only current stakeholders but also future stakeholders of the investment initialized by the project; broadening the spatial perspective to consider local, regional as well as global impacts of the project for stakeholders; using systemic working forms to allow for making the dynamics and complexities of the project and the project contexts better visible to the project manager, the project team, and the project owner; taking consequences in the project organization which lead to more integrative project organization structures to support cooperation on a project and with its stakeholders.