System of Systems (SoS) understanding, development, management, engineering, and operations remain extremely critical for the Department of War (DoW) as SoS are expected to dominate in nearly all future mission areas in peace and wartime alike. Moreover, SoS remains at the foundation of emerging concepts of distributed command-and-control systems and mission engineering. The DoW provided initial guidance on SoS via the “Systems Engineering (SE) Guide for SoS” that was published in 2008. Since its publication, the guide has been widely used to understand the unique challenges posed by SoS and has subsequently fueled a path of innovation for addressing SoS challenges by implementing seven core elements, as shown in the figure. However, the concept of SoS, at the time of this publication, was nascent in the research and engineering communities, but has experienced strides of progress in recent decades. Hence, the SE guide for SoS has largely become out of sync with the current innovations and guidance in SoS technical literature. It is imperative to update the DoW SE guidance on SoS with state-of-the-art standards and literature to help maintain its relevance and increase its utility to the DoW workforce.
The primary objective of this update is to support the Secretary of War’s memorandum, “Transforming the Defense Acquisition System into the Warfighting Acquisition System to Accelerate Fielding of Urgently Needed Capabilities to Our Warriors,” ensuring that SoS Engineering (SoSE) practices directly enhance the speed and effectiveness of capability delivery. Recognizing that SoS will dominate future mission areas in both peace and wartime, the Office of the Under Secretary of War for Research and Engineering (OUSW(R&E)) partnered with the Systems Engineering Research Center (SERC) and George Mason University (GMU) in 2025 to update the guidebook. This project aims to conduct a comprehensive review of the DoW SE guide for SoS and update it with the latest developments and knowledge from the academic literature, professional society standards, and industry best practices. This ensures that the SE guide for SoS not only remains relevant for use but also sets the guidance for the future of SoS for decades to come.
This project integrated the latest research and state-of-the-art standards to ensure the SoSE guidbook remains relevant and highly useful for the defense workforce. In summary, the GMU and SERC:
- Performed comprehensive reviews and contributed major revisions to the guidebook.
- Completed a literature review to support technical methods and references used in the guidebook.
- Enhanced guidebook content by integrating literature insights and structural improvements.
- Supported incorporation of subject matter expert feedback.
- Developed research concepts and submitted two papers for publication at the SoSE 2026 conference:
- Guidance for System of Systems Engineering Teams: How Core Elements Address Challenges.
- Agreement Processes and Enterprise Governance for SoS Evolution.