The aim of this strategic business consultancy project was the development of an applicable project management framework for sustainably successful M&A integration. Although M&As have been undertaken for decades throughout all industries, the reported high failure rates of M&A cases demonstrate the relevance of this topic and the need to create practical solutions. Therefore, this research aimed to answer the following central research question: How can a project management approach lead to a sustainably successful post-merger integration within an international real estate enterprise? The synthesis of findings from secondary and primary data led to the creation of an agile project management framework including the detailed elaboration of roles, routines, methods and tools. The framework Sprintegration® demonstrates the importance of holistic approaches including functional, operational and cultural integration, embedded in an agile system, which enables all involved stakeholders to consciously deal with the high complexity of M&As as the process of combining two previously separate companies and social systems.