Converged Security Maturity Index: A Unified Model for Cyber, Physical, and Operational Security Maturity Assessment

The growing integration of cyber, physical, and operational security functions has created a need for assessment approaches that evaluate security convergence as an organisational capability rather than as a set of isolated controls. This article proposes the Converged Security Maturity Index (CSMI), a conceptual maturity model designed to assess the level of integration among cybersecurity, physical security, and operational security within organisations. The model is developed using a design science research approach grounded in a structured review of converged security literature, cyber–physical system security, and existing maturity frameworks. CSMI comprises five progressive maturity levels—Fragmented, Coordinated, Integrated, Unified, and Optimised—and evaluates organisational capabilities across four dimensions: governance and strategy, processes and incident management, technology and infrastructure integration, and human factors and organisational culture. The article describes the architecture of the model and the rationale for each maturity level and dimension and outlines how the framework could be applied in practice through a structured questionnaire in future work. The proposed framework aims to support organisational self-assessment, benchmarking, and identification of convergence gaps across different sectors.