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] referred to system of systems engineering.
Commonly proposed descriptions—not necessarily definitions—of systems of systems, [2] are outlined below in order of their appearance in the literature:
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.
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]
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]
Current research into effective approaches to system of systems problems includes:
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.
Collaboration among a wide array of organizations is helping to drive the 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 agencies.
Major stakeholders in the development of this concept are:
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:
Ongoing European projects which are using a System of Systems approach include:
Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their life cycles. At its core, systems engineering utilizes systems thinking principles to organize this body of knowledge. The individual outcome of such efforts, an engineered system, can be defined as a combination of components that work in synergy to collectively perform a useful function.
Design for Six Sigma (DFSS) is a collection of best-practices for the development of new products and processes. It is sometimes deployed as an engineering design process or business process management method. DFSS originated at General Electric to build on the success they had with traditional Six Sigma; but instead of process improvement, DFSS was made to target new product development. It is used in many industries, like finance, marketing, basic engineering, process industries, waste management, and electronics. It is based on the use of statistical tools like linear regression and enables empirical research similar to that performed in other fields, such as social science. While the tools and order used in Six Sigma require a process to be in place and functioning, DFSS has the objective of determining the needs of customers and the business, and driving those needs into the product solution so created. It is used for product or process design in contrast with process improvement. Measurement is the most important part of most Six Sigma or DFSS tools, but whereas in Six Sigma measurements are made from an existing process, DFSS focuses on gaining a deep insight into customer needs and using these to inform every design decision and trade-off.
The ARIS concept by August-Wilhelm Scheer aims to ensure that an enterprise information system can completely meet its requirements.
The British Ministry of Defence Architecture Framework (MODAF) was an architecture framework which defined a standardised way of conducting enterprise architecture, originally developed by the UK Ministry of Defence. It has since been replaced with the NATO Architecture Framework.
An enterprise architecture framework defines how to create and use an enterprise architecture. An architecture framework provides principles and practices for creating and using the architecture description of a system. It structures architects' thinking by dividing the architecture description into domains, layers, or views, and offers models – typically matrices and diagrams – for documenting each view. This allows for making systemic design decisions on all the components of the system and making long-term decisions around new design requirements, sustainability, and support.
Model-driven engineering (MDE) is a software development methodology that focuses on creating and exploiting domain models, which are conceptual models of all the topics related to a specific problem. Hence, it highlights and aims at abstract representations of the knowledge and activities that govern a particular application domain, rather than the computing concepts.
System of systems engineering (SoSE) is a set of developing processes, tools, and methods for designing, re-designing and deploying solutions to system-of-systems challenges.
Enterprise modelling is the abstract representation, description and definition of the structure, processes, information and resources of an identifiable business, government body, or other large organization.
Virtual engineering (VE) is defined as integrating geometric models and related engineering tools such as analysis, simulation, optimization, and decision making tools, etc., within a computer-generated environment that facilitates multidisciplinary collaborative product development. Virtual engineering shares many characteristics with software engineering, such as the ability to obtain many different results through different implementations.
Enterprise engineering is the body of knowledge, principles, and practices used to design all or part of an enterprise. An enterprise is a complex socio-technical system that comprises people, information, and technology that interact with each other and their environment in support of a common mission. One definition is: "an enterprise life-cycle oriented discipline for the identification, design, and implementation of enterprises and their continuous evolution", supported by enterprise modelling. The discipline examines each aspect of the enterprise, including business processes, information flows, material flows, and organizational structure. Enterprise engineering may focus on the design of the enterprise as a whole, or on the design and integration of certain business components.
A view model or viewpoints framework in systems engineering, software engineering, and enterprise engineering is a framework which defines a coherent set of views to be used in the construction of a system architecture, software architecture, or enterprise architecture. A view is a representation of the whole system from the perspective of a related set of concerns.
Core architecture data model (CADM) in enterprise architecture is a logical data model of information used to describe and build architectures.
Generalised Enterprise Reference Architecture and Methodology (GERAM) is a generalised enterprise architecture framework for enterprise integration and business process engineering. It identifies the set of components recommended for use in enterprise engineering.
Peter Bernus is a Hungarian Australian scientist and Associate Professor of Enterprise Architecture at the School of Information and Communication Technology, Griffith University, Brisbane, Australia.
Modeling and simulation (M&S) is the use of models as a basis for simulations to develop data utilized for managerial or technical decision making.
Live, Virtual, & Constructive (LVC) Simulation is a broadly used taxonomy for classifying Modeling and Simulation (M&S). However, categorizing a simulation as a live, virtual, or constructive environment is problematic since there is no clear division among these categories. The degree of human participation in a simulation is infinitely variable, as is the degree of equipment realism. The categorization of simulations also lacks a category for simulated people working real equipment.
Systems modeling or system modeling is the interdisciplinary study of the use of models to conceptualize and construct systems in business and IT development.
MULTICUBE is a Seventh Framework Programme (FP7) project aimed to define innovative methods for the design optimization of computer architectures for the embedded system domain.
Model Driven Interoperability (MDI) is a methodological framework, which provides a conceptual and technical support to make interoperable enterprises using ontologies and semantic annotations, following model driven development (MDD) principles.
Purdue Enterprise Reference Architecture (PERA), or the Purdue model, is a 1990s reference model for enterprise architecture, developed by Theodore J. Williams and members of the Industry-Purdue University Consortium for Computer Integrated Manufacturing.