This research proposal aims to investigate the effectiveness of using a visualization tool called the Stakeholder Circle to support project managers in managing stakeholders and building sustainable relationships for project success. The study will use a deductive, exploratory approach with purposive sampling of 5 projects across different industries lasting approximately 6 months each. Both interviews and diaries will be used to collect data at the beginning and end of projects to track stakeholder relationship issues and changes over time. The objectives are to identify ways to improve building and maintaining sustainable project relationships and to determine the effectiveness of the Stakeholder Circle tool for stakeholder management.