In today’s application engineering, the implementation of frameworks and related technology boosts development quality and reduces related effort. Framework functionality embodies expert knowledge and is driven towards reuse. While stable from a conceptual point of view, technological changes require constant adaptation and reengineering. This article presents overall framework engineering principles and practices (FEPP) and shows their concrete application using the example of the Microsoft Foundation Classes. Abstracting from the case study, the focus of this work is upon introducing particular methods for how to cut down on the complexity of maintenance projects by considering the FEPP during framework development.