George Rebovich

An implementers' view of systems engineering for systems of systems

This paper builds on and extends U.S. Department of Defense published guidance on systems engineering (SE) of systems of systems (SoS) by developing and presenting a view of SoS SE that translates the SoS SE core elements, their interrelationships, and SoS decision-making artifacts and information from a “trapeze” model to a more familiar and intuitive time-sequenced “wave” model representation. The information is thus rendered in a form more readily usable by SoS SE practitioners in the field and one that corresponds with incremental development approaches that are the norm for SoS capability evolution. The paper describes and motivates the development of the wave model, discusses its key characteristics, and provides examples of SoS efforts that reflect this view of SoS SE. Finally, the paper describes how the information critical to successful SoS SE is created, where it fits into the wave model, how it evolves over time, and in which artifacts the information is normally contained.

A Fuzzy Evaluation method for System of Systems Meta-architectures☆

Abstract A method is proposed for evaluating a range of System of Systems (SoS) meta-architecture alternatives. SoS are composed through combination of existing, fully functioning Systems, possibly with minor functional changes, but certainly by using the combined Systems to achieve a new capability, not available from the Systems alone. The meta-architecture describes how all possible subsets of Systems can be combined to create an SoS. The fitness of a realizable SoS architecture may be characterized by terms such as unacceptable, marginal, above average, or excellent. While these terms provide little information about the SoS when used alone and informally, they readily fit into fuzzy membership sets that overlap at their boundaries. More descriptive attributes such as “ease of use,” which might depend on individual user and a set of conditions, “mission effectiveness” over a particular suite of missions, and “affordability,” which may change over time with changing business climate, etc., lend themselves readily to fuzzy evaluation as well. An approach to defining the fuzzy concepts and establishing rule sets to provide an overall SoS evaluation for many sets of participating individual Systems represented by the meta-architecture is discussed. An application of the method is discussed within the framework of developing and evaluating a hypothetical Intelligence, Surveillance and Reconnaissance (ISR) SoS capability.

Systems of systems test and evaluation challenges

A growing number of military capabilities are achieved through a system of system approach and this trend is likely to continue in the foreseeable future. Systems of systems differ from traditional systems in ways that require tailoring of systems engineering processes to successfully deliver their capabilities. This paper describes the distinct characteristics of systems of systems that impact their test and evaluation, discusses their unique challenges, and suggests strategies for managing them. The recommendations are drawn from the experiences of active system of system engineering practitioners.

Security engineering in a system of systems environment

Systems engineering (SE) of defense systems and critical infrastructure must incorporate consideration of threats and vulnerabilities to malicious subversion into the engineering requirements, architecture, and design processes. Recognizing this need, the United States Department of Defense recently revitalized its system security engineering (SSE) efforts by extending its program protection processes to apply SSE principles and body of knowledge to defense acquisition programs [1]. At the same time, a growing number of military capabilities are being fielded through system of systems (SoS) approaches which are not necessarily managed under formal acquisition processes. This trend is expected to continue. Recognizing this trend, several years ago the DoD undertook an initiative to develop initial guidance on the system engineering of SoS [3]. In the ensuing years, a companion body of knowledge has been developed [4]. More recently, the importance and the challenges of applying SSE beyond individual systems to SoS has been recognized [4]. The question arises, “what does or should SSE look like in an SoS environment?” This paper presents the results of an exploratory investigation of SSE as an integral element of SoS SE. Defense-based approaches to SoS SE are reviewed and logical extensions to address SSE for SoS and program protection are described within an SoS SE framework. The results of case studies exploring how SoS currently address security at the SoS level are presented. Finally, observations and challenges are discussed, including whether and how guidelines and practices for SSE at the individual or constituent system level can be extended to the ensemble of systems that collectively create an SoS capability.

Systems thinking for the enterprise: new and emerging perspectives

New and emerging modes of thought are increasingly being recognized as essential to successful systems engineering in enterprises. This new systems thinking is emerging at the intersection of seminal ideas from modern system thinkers, the broad discipline of information technology, and the theory of complex adaptive systems, particularly those from evolutionary biology and social systems. Part of this new systems thinking requires a replacement of the notion that specific engineering outcomes or goals can always be assured with one that seeks to shape, improve, or increase the value of engineering outcomes through thoughtful interventions in the ever-increasing numbers of circumstances in which we are not fully in control

The Evolution of Systems Engineering

The 21st century is an exciting time for the field of systems engineering. Advances in our understanding of the traditional discipline are being made. At the same time new modes of systems engineering are emerging to address the engineering challenges of systems-of-systems (SoS) and enterprise systems. Even at this early point in their evolution, these new modes are evincing their own principles, processes and practices. Some are different in degree than engineering at the system level while others are different in kind. While it is impossible to predict how the traditional and new forms of systems engineering will evolve, it is clear even now that there is a long and robust future for all three. Increases in technology complexity have led to new challenges in architecture, networks, hardware and software engineering, and human systems integration. At the same time, the scale at which systems are engineered is exceeding levels that could have been imagined only a short time ago. As a consequence, all three forms of systems engineering will be needed to solve the engineering problems of the future, sometimes separately but increasingly in combination. This paper defines three modes of systems engineering, discusses the challenge space each addresses, describes how they differ from and complement each other. It asks and starts to answer the question of how to enable the development of enterprise systems engineering in a defense department.

Patterns of Success in Systems Engineering of IT-Intensive Government Systems

The objective of this effort was to discover patterns of success in the systems engineering of information-intensive systems in a government acquisition environment using the method of positive deviance. Two large-scale success patterns were observed, each with several recurring sub-patterns. “Balancing the Supply Web” addresses “social” interdependencies among enterprise stakeholders who have different equities in the capability being developed. “Harnessing Technical Complexity” addresses the technical interdependencies among system components that together deliver an operational capability for the enterprise. The large-scale patterns are two sides of the same coin. The programs studied achieved success because of the way they each navigated through these dual interdependencies.

System engineering artifacts for SoS

This paper describes system of systems (SoS) systems engineering (SE) artifacts, compares and contrasts them with similar ones developed and used for individual systems, and explains how they are used to guide SoS engineering processes. The paper concludes with next steps for using SoS artifacts to continue maturing the understanding of SoS SE in an international cooperative effort with the United Kingdom, Australia, and Canada.

An actionable framework for system of systems and mission area security engineering

This paper describes an actionable engineering framework for security engineering of a system of systems (SoS). The framework is envisioned as a tool for assessing security risks to critical missions based on the contributing systems and SoS supporting them. An SoS security risk framework is needed to manage the problem of identifying the key elements of risk to SoS missions. The issue is the complexity resulting from the large number of potential logical paths through an SoS that could represent a security risk. Managing this problem then enables the application of security specific analyses to the SoS elements that have been identified as critical. The framework draws on the foundational elements of SoS SE, particularly an understanding of the SoS components, interdependencies and dynamics. The results of the analysis support investment decisions about the constituents of a SoS. The framework is a bridge between the operational and acquisition/engineering communities. While the focus of this framework is on acquisition and engineering materiel solutions, it also accommodates the consideration of non-materiel solutions.

Improving the practice of systems engineering: Boot strapping grass roots success

This paper describes how to use a positive deviance-inspired process for improving the practice of systems engineering, and how positive deviance fits into an evolutionary improvement strategy. It illustrates the process with examples from both systems engineering and cases studies outside of systems engineering. In particular we cite the experience of the team that authored the DoD Systems Engineering Guide for Systems of Systems (SoS) [Ref 1]. They developed a representation of how successful SoS engineering practitioners view and do systems engineering that is substantially different from their individual system counterparts. The cases outside of systems engineering relate to an antistarvation program in rural Vietnam and a 150-year old problem of inadequate hand scrubbing and infections in hospitals [Ref 2]. Even with substantial progress in technology, processes, and efficiencies, complex problems from enterprise systems engineering to nutrition to medical needs still stubbornly resist improvement. By using a positive deviance-inspired approach, this can be reversed.