Flexible customer and supplier relationships are now among the key competitive factors. Flexibility-oriented framework agreements are a common tool to increase responsiveness while simultaneously mitigating demand and inventory risks. However, there is still a lack of tangible models and methods that ensure operational implementation for material management. Nikolai Iliev integrates common contract types into a standardized demand model that is understandable and allows for practical handling. The robust calculation model is sufficiently accurate for depicting inventory risks and can decisively support questions of risk allocation between manufacturer and customer during contract negotiations. By clarifying the concept of flexibility in material management, cross-industry application possibilities are created.