Interoperability Mechanisms for System-of-Systems: A Systematic Literature Review
Systems-of-Systems (SoS) engineering faces the intrinsic challenge of orchestrating cooperation among operationally and managerially independent Constituent Systems (CSs). This paper presents a Systematic Literature Review (SLR) on interoperability and integration mechanisms employed in SoS architectures across multiple application domains. Following the guidelines by Kitchenham and Charters and the PRISMA checklist, 58 primary studies were systematically selected and analyzed, addressing three research questions on 1) the predominant mediation mechanisms and enabling technologies, 2) the architectural patterns that support the independent evolution of CSs, and 3) recurrent technical limitations. The selected studies span ten application domains, including defense, energy, transportation, industry, and smart cities, and cover five families of mediation mechanisms, providing a broad and traceable evidence base for researchers and practitioners seeking to understand the current landscape of SoS integration. The results indicate a hegemony of decentralized, agent-based approaches, with co-simulation platforms, semantic mediators, and middleware gateways also present across diverse domains. Taken together, the findings reveal a fragmented landscape: mechanisms are frequently proposed in isolation and evaluated in narrow domain-specific scenarios, with limited cross-mechanism comparison among primary studies and scarce guidance on how to organize mediators in adaptive SoS architectures. These results expose an open gap for lightweight integration mechanisms capable of operating at the boundaries of constituent systems without requiring development effort from their teams, a direction that remains largely unexplored in the literature.