SOS for SoS: A new paradigm for system of systems modeling

Systems of Systems (SoS) modeling is becoming increasingly important in both civilian and military systems. The Department of Defense (DoD) Defense Acquisition Guidebook, [1] defines a SoS as a “set or arrangement of systems that results when independent and useful systems are integrated into a larger system that delivers unique capabilities.” Organizations are changing their emphasis from “We need a new system” to “We need to achieve a specific outcome.” As these outcomes become more complex and the associated systems more complex, the management, modeling and simulation of these SoS becomes equally challenging. Often, the SoS is modeled in all its complexity, often at a single level of abstraction or level of detail. Instead of a “megamodel” approach, a standards-based “model of models” approach is what is necessary. This approach will use the Object Management Group (OMG) Unified Profile for DoDAF and MODAF (UPDM) for modeling enterprise architectures from capabilities to detailed components, and the Reusable Asset Specification (RAS) for defining reusable assets. Combining UPDM and RAS provides a Model of Models approach with the main model specifying assets in various levels of details. The models specified by these assets can be referenced when detailed analysis is required, or hidden when a SoS viewpoint is required, allowing the analyst to see the forest through the trees. The paper will also include an assessment of the applicability and effectiveness of this approach. The International Conference on Systems Engineering (INCOSE) System of Systems Working Group (SoSWG) has collected a set of “Pain Points on SoS” from a variety of international sources. This paper will review these pain points and discuss how the application of a Model of Model approach, combined with standards-based modeling tools and a reusable assets approach can help to alleviate some of the pain currently being felt by SoS architects and managers. Hopefully, this response to their SOS will deliver some much-needed assistance.