The purpose of this article is to develop a model of family business that accounts for the unique characteristics and diversity of family businesses and addresses the dynamics among family business subsystems. An open-systems approach serves as the conceptual foundation of the model. The distinctive features of the proposed model are the multiple levels of analysis and the dynamics and interdependencies among the subsystems, allowing the integration of mainstream theories. The model can serve to discover and explore a relevant research question in the context of family business, which may help researchers advance theory building on family business. Furthermore, the model may help family business practitioners better understand the particularities of family firms.