Background: Organizational architecture is a holistic approach to design of humane organizations and studies an organization from five perspectives: structure, culture, processes, strategy and individuals. In this paper, the concept of organizational architecture is firstly formalized using the fractal principle and then applied to multi-agent systems’ (MAS) organizations. Objectives: Providing a holistic framework for modeling all aspects of MAS reorganization. Methods/Approach: MAS organizations are formalized using graph theoryand a new active graph rewriting formalism inspired by active database theory is intoduced. Results: The newly developed framework is graphical, event-driven and applicable in a distributed MAS environment. Conclusions: By defining organizational units, processes, strategies and cultural artefacts in a recursive way, it is shown that labeled graphs andhypergraphs can be used to model various levels of organizational architecture while active graph grammars allow one to model reorganization of each of the architectural perspectives.