Separation of Duty (SoD) is a fundamental principle in information security. Especially large and highly regulated companies have to manage a huge number of SoD policies. These policies need to be maintained in an ongoing effort in order to remain accurate and compliant with regulatory requirements. In this work we develop a framework for managing SoD policies that pays particular attention to policy comprehensibility. We conducted seven semi-structured interviews with SoD practitioners from large organizations in order to understand the requirements for managing and maintaining SoD policies. Drawing from the obtained insights, we developed a framework, which includes the relevant stakeholders and tasks, as well as a policy structure that aims to simplify policy maintenance. We anchor the proposed policy structure in a generic IAM data model to ensure compatibility and flexibility with other IAM models. We then show exemplary how our approach can be enforced within Role-Based Access Control. Finally, we evaluate the proposed framework with a real-world IAM data set provided by a large finance company.