System of systems

System of systems is a collection of task-oriented or dedicated systems that pool their resources and capabilities together to create a new, more complex system which offers more functionality and performance than simply the sum of the constituent systems. Currently, systems of systems is a critical research discipline for which frames of reference, thought processes, quantitative analysis, tools, and design methods are incomplete.^[1] The methodology for defining, abstracting, modeling, and analyzing system of systems problems is typically referred to as system of systems engineering.

Overview

Commonly proposed descriptions—not necessarily definitions—of systems of systems,^[2] are outlined below in order of their appearance in the literature:

1. Linking systems into joint system of systems allows for the interoperability and synergism of Command, Control, Computers, Communications and Information (C4I) and Intelligence, Surveillance and Reconnaissance (ISR) Systems:^[3] description in the field of information superiority in modern military.
2. System of systems are large-scale concurrent and distributed systems the components of which are complex systems themselves:^[4] description in the field of communicating structures and information systems in private enterprise.
3. System of systems education involves the integration of systems into system of systems that ultimately contribute to evolution of the social infrastructure:^[5] description in the field of education of engineers on the importance of systems and their integration.
4. System of systems integration is a method to pursue development, integration, interoperability and optimization of systems to enhance performance in future battlefield scenarios:^[6] description in the field of information intensive systems integration in the military.
5. Modern systems that comprise system of systems problems are not monolithic, rather they have five common characteristics: operational independence of the individual systems, managerial independence of the systems, geographical distribution, emergent behavior and evolutionary development:^[7] description in the field of evolutionary acquisition of complex adaptive systems in the military.
6. Enterprise systems of systems engineering is focused on coupling traditional systems engineering activities with enterprise activities of strategic planning and investment analysis:^[8] description in the field of information intensive systems in private enterprise.
7. System of systems problems are a collection of trans-domain networks of heterogeneous systems that are likely to exhibit operational and managerial independence, geographical distribution, and emergent and evolutionary behaviors that would not be apparent if the systems and their interactions are modeled separately:^[9] description in the field of National Transportation System, Integrated Military and Space Exploration.

Taken together, all these descriptions suggest that a complete system of systems engineering framework is needed to improve decision support for system of systems problems. Specifically, an effective system of systems engineering framework is needed to help decision makers to determine whether related infrastructure, policy and/or technology considerations as an interrelated whole are good, bad or neutral over time.^[10] The need to solve system of systems problems is urgent not only because of the growing complexity of today's challenges, but also because such problems require large monetary and resource investments with multi-generational consequences.

System-of-systems topics

The system-of-systems approach

While the individual systems constituting a system of systems can be very different and operate independently, their interactions typically expose and deliver important emergent properties. These emergent patterns have an evolving nature that stakeholders must recognize, analyze and understand. The system of systems approach does not advocate particular tools, methods or practices; instead, it promotes a new way of thinking for solving grand challenges where the interactions of technology, policy, and economics are the primary drivers. System of systems study is related to the general study of designing, complexity and systems engineering, but also brings to the fore the additional challenge of design.

Systems of systems typically exhibit the behaviors of complex systems, but not all complex problems fall in the realm of systems of systems. Inherent to system of systems problems are several combinations of traits, not all of which are exhibited by every such problem:^[11][12]

• Operational Independence of Elements
• Managerial Independence of Elements
• Evolutionary Development
• Emergent Behavior
• Geographical Distribution of Elements
• Interdisciplinary Study
• Heterogeneity of Systems
• Networks of Systems

The first five traits are known as Maier's criteria^[13] for identifying system of systems challenges. The remaining three traits have been proposed from the study of mathematical implications of modeling and analyzing system of systems challenges by Dr. Daniel DeLaurentis^[14] and his co-researchers at Purdue University.^[15]

Research

Current research into effective approaches to system of systems problems includes:

• Establishment of an effective frame of reference
• Crafting of a unifying lexicon ^[16]
• Developing effective methodologies to visualize and communicate complex systems ^[17]
• Distributed resource management ^[18]
• Study of designing architecture
  • Interoperability ^[19]
  • Data distribution policies: policy definition, design guidance and verification^[20]
• Formal modelling language with integrated tools platform^[21]
• Study of various modeling, simulation and analysis techniques
  • network theory
  • agent based modeling
  • general systems theory
  • probabilistic robust design (including uncertainty modeling/management)
  • object-oriented simulation and programming
  • multi-objective optimization
• Study of various numerical and visual tools for capturing the interaction of system requirements, concepts and technologies

Applications

Systems of systems, while still being investigated predominantly in the defense sector, is also seeing application in such fields as national air and auto transportation^[22] and space exploration. Other fields where it can be applied include health care, design of the Internet, software integration, and energy management^[19] and power systems.^[23] Social-ecological interpretations of resilience, where different levels of our world (e.g., the Earth system, the political system) are interpreted as interconnected or nested systems, take a systems-of-systems approach. An application in business can be found for supply chain resilience.

Educational institutions and industry

Collaboration among wide array of organizations is helping to drive development of defining system of systems problem class and methodology for modeling and analysis of system of systems problems. There are ongoing projects throughout many commercial entities, research institutions, academic programs, and government agences.

Major stakeholders in the development of this concept are:

• Universities working on system of systems problems, including Purdue University, the Georgia Institute of Technology, Old Dominion University, George Mason University, the University of New Mexico, the Massachusetts Institute of Technology, Naval Postgraduate School and Carnegie Mellon University.
• Corporations active in this area of research such as The MITRE Corporation, Airbus, BAE Systems, Northrop Grumman, Boeing, Raytheon, Thales Group, CAE Inc., Altair Engineering, Saber Astronautics and Lockheed Martin.
• Government agencies that perform and support research in systems of systems research and applications, such as DARPA, the U.S. Federal Aviation Administration, NASA and Department of Defense (DoD)

For example, DoD recently established the National Centers for System of Systems Engineering^[24] to develop a formal methodology for system-of-systems engineering for applications in defense-related projects.

In another example, according to the Exploration Systems Architecture Study, NASA established the Exploration Systems Mission Directorate (ESMD) organization to lead the development of a new exploration "system-of-systems" to accomplish the goals outlined by President G.W. Bush in the 2004 Vision for Space Exploration.

A number of research projects and support actions, sponsored by the European Commission, were performed in the Seventh Framework Programme. These target Strategic Objective IST-2011.3.3 in the FP7 ICT Work Programme (New paradigms for embedded systems, monitoring and control towards complex systems engineering). This objective had a specific focus on the "design, development and engineering of System-of-Systems". These projects included:

• T-AREA-SoS^[25] (Trans-Atlantic Research and Education Agenda on Systems of Systems), which aims "to increase European competitiveness in, and improve the societal impact of, the development and management of large complex systems in a range of sectors through the creation of a commonly agreed EU-US Systems of Systems (SoS) research agenda".
• COMPASS^[21] (Comprehensive Modelling for Advanced Systems of Systems), aiming to provide a semantic foundation and open tools framework to allow complex SoSs to be successfully and cost-effectively engineered, using methods and tools that promote the construction and early analysis of models.
• DANSE^[26] (Designing for Adaptability and evolutioN in System of systems Engineering), which aims to develop "a new methodology to support evolving, adaptive and iterative System of Systems life-cycle models based on a formal semantics for SoS inter-operations and supported by novel tools for analysis, simulation, and optimisation".
• ROAD2SOS^[27] (Roadmaps for System-of-System Engineering), aiming to develop "strategic research and engineering roadmaps in Systems of Systems Engineering and related case studies".
• DYMASOS^[28] (DYnamic MAnagement of physically-coupled Systems Of Systems), aiming to develop theoretical approaches and engineering tools for dynamic management of SoS based on industrial use cases.
• AMADEOS^[29] (Architecture for Multi-criticality Agile Dependable Evolutionary Open System-of-Systems) aiming to bring time awareness and evolution into the design of System-of- Systems (SoS) with possible emergent behavior, to establish a sound conceptual model, a generic architectural framework and a design methodology.

Ongoing European projects which are using a System of Systems approach include:

• Arctic PASSION^[30] (Pan-Arctic observing System of Systems: Implementing Observations for societal Needs; July 2021 - June 2025) is a Horizon_2020 research project with the key motivation of co-creating and implementing a coherent, integrated Arctic observing system: the Pan-Arctic Observing System of Systems - pan-AOSS. The project aims to overcome shortcomings in the present observing system by refining its operability, improving and extending pan-Arctic scientific and community-based monitoring and the integration with indigenous and local knowledge.
• COLOSSUS^[31] (Collaborative System of Systems Exploration of Aviation Products, Services and Business Models; Feb 2023 - Jan 2026) is a Horizon_Europe research project for the development of a system-of-systems design methodology which for the first time will enable the combined optimization of aircraft, operations and business models. The project aims at establishing a transformative digital collaborative (TDC) framework to enable European aviation to conduct research, technology development, and innovation. The TDC framework will support the simulation, analysis, optimization and evaluation of complex products and services in real-world scenarios.

See also

• Inheritance
• Software library
• Object-oriented programming
• Model-based systems engineering
• Enterprise systems engineering
• Complex adaptive system
• Systems architecture
• Process architecture
• Software architecture
• Enterprise architecture
• Ultra-large-scale systems
• Department of Defense Architecture Framework
• New Cybernetics

References

1. Popper, S., Bankes, S., Callaway, R., and DeLaurentis, D., System-of-Systems Symposium: Report on a Summer Conversation 2011-09-28 at the Wayback Machine, July 21–22, 2004, Potomac Institute for Policy Studies, Arlington, VA.
2. collected partly from: [1] 2005-10-15 at the Wayback Machine Jamshidi, M., "System-of-Systems Engineering - A Definition," IEEE SMC 2005, 10-12 Oct. 2005.
3. Manthorpe Jr., W.H., "The Emerging Joint System-of-Systems: A Systems Engineering Challenge and Opportunity for APL," Johns Hopkins APL Technical Digest, Vol. 17, No. 3 (1996), pp. 305–310. [2] 2006-09-03 at the Wayback Machine
4. Kotov, V. "Systems-of-Systems as Communicating Structures," Hewlett Packard Computer Systems Laboratory Paper HPL-97-124, (1997), pp. 1–15. [3]
5. Luskasik, S.J. "Systems, Systems-of-Systems, and the Education of Engineers 2019-06-04 at the Wayback Machine," Artificial Intelligence for Engineering Design, Analysis, and Manufacturing, Vol. 12, No. 1 (1998), pp. 55-60.
6. Pei, R.S., "Systems-of-Systems Integration (SoSI) – A Smart Way of Acquiring Army C4I2WS Systems," Proceedings of the Summer Computer Simulation Conference, (2000), pp. 574-579.
7. Sage, A.P.; Cuppan, C.D. (2001). (PDF). Information, Knowledge, Systems Management. 2 (4): 325–345. S2CID 7609190. Archived from the original (PDF) on 2019-06-04.
8. Carlock, P.G., and R.E. Fenton. "System-of-Systems (SoS) Enterprise Systems for Information-Intensive Organizations," Systems Engineering, Vol. 4, No. 4 (2001), pp. 242-261.
9. DeLaurentis, D. "Understanding Transportation as a System of Systems Design Problem," 43rd AIAA Aerospace Sciences Meeting, Reno, Nevada, January 10–13, 2005. AIAA-2005-0123. [4]
   DeLaurentis, D. A.; Callaway, R. K. (2004). "A System of Systems Perspective for Future Public Policy". Review of Policy Research. 21 (6): 829–837. doi:10.1111/j.1541-1338.2004.00111.x.
10. [5] DeLaurentis, D., Callaway, R.K., "A System-of-Systems Perspective for Public Policy Decisions," Review of Public Policy Research, Vol. 21, Issue 6, Nov. 2004, pp. 829-837.
11. [6] DeLaurentis, D., "Research Foundations," School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN, 2007.
12. Boardman, John, DiMario, Michael, Sauser, Brian, Verma, Dinesh, "System of Systems Characteristics and Interoperability in Joint Command and Control", Defense Acquisition University, 25–26 July 2006 [7] 2011-07-19 at the Wayback Machine
13. Maier, M.W. (1998). "Architecting Principles for System of Systems". Systems Engineering. 1 (4): 267–284. doi:10.1002/(sici)1520-6858(1998)1:4<267::aid-sys3>3.0.co;2-d. Retrieved 2012-12-13.
14. DeLaurentis, D. "Understanding Transportation as a System of Systems Design Problem," 43rd AIAA Aerospace Sciences Meeting, Reno, Nevada, January 10–13, 2005. AIAA-2005-0123. [8]
15. [9] "Systems of Systems (SoS)," College of Engineering, Purdue University, West Lafayette, IN, 2007.
16. [10] DeLaurentis D., "System of Systems Definition and Vocabulary," School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN, 2007.
17. Jara, F. (1998, July 24). Visualization systems. Retrieved from web http://www.cs.uml.edu/~fjara/thesis/active/proposal/node6.html 2012-04-15 at the Wayback Machine on 16 Nov 2011
18. Mosleh M., Ludlow P., Heydari B., "Distributed Resource Management in System of Systems: An Architecture Perspective", Systems Engineering, 2016
19. Curry, Edward. 2012. "System of Systems Information Interoperability Using a Linked Dataspace." In IEEE 7th International Conference on System of Systems Engineering (SOSE 2012), 101–106.
20. Gianni, D., (2015, Jan). Data Policy Definition and Verification for System of Systems Governance, in Modeling and Simulation Support for System of Systems Engineering [11]
21. . Archived from the original on 2021-09-21. Retrieved 2013-07-15.
22. Parker, J. (2010) "Applying a system of systems approach for improved transportation". S.A.P.I.EN.S. 3 (2)
23. Kremers, E., Viejo, P., Barambones, O., Durana, J., (2010). A Complex Systems Modelling Approach for Decentralised Simulation of Electrical Microgrids. Proceedings of the 15th IEEE International Conference on Engineering of Complex Computer Systems (ICECCS), 2010. https://doi.org/10.1109/ICECCS.2010.1
24. National Centers for System-of-Systems Engineering
25. . Archived from the original on 2013-05-16. Retrieved 2013-07-22.
26. Designing for Adaptability and evolutioN in System of systemsEngineering
27. Roadmaps for SoS Engineering
28. Dynamic Management of Physically-coupled Systems Of Systems (DYMASOS)
29. . Archived from the original on 2014-08-24. Retrieved 2015-12-18.
30. Pan-Arctic observing System of Systems: Implementing Observations for societal Needs (Arctic PASSION); CORDIS reference: [12]
31. Collaborative System of Systems Exploration of Aviation Products, Services and Business Models (COLOSSUS); CORDIS reference: [13]

Further reading

• Yaneer Bar-Yam et al. (2004) "The Characteristics and Emerging Behaviors of System-of-Systems" in: NECSI: Complex Physical, Biological and Social Systems Project, January 7, 2004.
• Kenneth E. Boulding (1954) "General Systems Theory - The Skeleton of Science," Management Science, Vol. 2, No. 3, ABI/INFORM Global, pp. 197–208.
• Crossley, W.A., System-of-Systems:, Introduction of Purdue University Schools of Engineering's Signature Area.
• Mittal, S., Martin, J.L.R. (2013) Netcentric System of Systems Engineering with DEVS Unified Process, CRC Press, Boca Raton, FL
• DeLaurentis, D. "Understanding Transportation as a System of Systems Design Problem," 43rd AIAA Aerospace Sciences Meeting, Reno, Nevada, January 10–13, 2005. AIAA-2005-0123.
• J. Lewe, D. Mavris, [14]^{[permanent dead link]} Foundation for Study of Future Transportation Systems Through Agent-Based Simulation}, in: Proceedings of 24th International Congress of the Aeronautical Sciences (ICAS), Yokohama, Japan, August 2004. Session 8.1.
• Maier, M.W. (1998). "Architecting Principles for System of Systems". Systems Engineering. 1 (4): 267–284. doi:10.1002/(sici)1520-6858(1998)1:4<267::aid-sys3>3.0.co;2-d. Retrieved 2012-12-13.
• Held, J.M.,The Modelling of Systems of Systems, PhD Thesis, University of Sydney, 2008
• D. Luzeaux & J.R. Ruault, "Systems of Systems", ISTE Ltd and John Wiley & Sons Inc, 2010
• D. Luzeaux, J.R. Ruault & J.L. Wippler, "Complex Systems and Systems of Systems Engineering", ISTE Ltd and John Wiley & Sons Inc, 2011
• Popper, S., Bankes, S., Callaway, R., and DeLaurentis, D. (2004) System-of-Systems Symposium: Report on a Summer Conversation, July 21–22, 2004, Potomac Institute for Policy Studies, Arlington, VA.

External links

• System of Systems - video IBM
• "A Smarter Planet blog - The Internet of Things and System of Systems". IBM. October 2015.
• IEEE International Conference on System of Systems Engineering (SoSE)
• System of Systems, Systems Engineering Guide (USD AT&L Aug 2008)
• International Journal of System of Systems Engineering (IJSSE)