The two major IS design science research schools have a focus on IT artifacts and have very little discussions regarding underpinning philosophies. We present a framework for IS design science research underpinned by the philosophy of critical realism. We argue that the aim of IS design science research is to develop practical and actionable knowledge for the design and realization of different classes of IS initiatives, where IS are viewed as socio-technical systems. The paper presents how this type of knowledge can be developed as well as the nature of such knowledge.