System-of-systems Research Articles

Analyzing the Environmental Consequences of Production Processes from a System of Systems Perspective: A Case of Gear Manufacturing in the Automotive Industry

Many research studies have been done to investigate different aspects of environmental challenges. In the product development context, there have been attempts to reduce the environmental impacts of associated activities including the production processes themselves. As a result, various technological improvements have been made and new production processes e.g. powder metallurgy technologies have been introduced that may demonstrate a lower environmental footprint compared to conventional processes e.g. cutting machining technologies. However, a production process with a lower environmental impact may lead to reducing the quality/performance attributes of the produced parts (gear) and probably of final products (transmission box). Therefore, the efforts intended to produce more sustainable products by using production processes with less environmental footprints may lead to some unintended consequences such as increased maintenance requirements and/or demand. This is a rebound effect from a system of systems (SoS) perspective. This paper aims to analyze the impacts of more environmentally friendly production processes on the total environmental impact associated with a product given they may have a negative impact on a part/product’s quality and performance or usage. This paper introduces a methodological approach to analyze the environmental sustainability of a production process at a SoS level. This is done by including the entire supply chain of a product-system and its interacting systems by using the results of the attributional/consequential life cycle assessment (LCA) method. The approach validity approach is demonstrated in the case of gear manufacturing in the automotive industry.

A comparison of the system engineering standard and INCOSE Complexity Primer

Complexity is frequently used to describe the environment in which systems engineering must work. Relevant publications establish a relationship between complexity and understanding, however, it is questionable whether system engineering methodologies are well suited to deal with complexity and potential lack of understanding. This paper provides an analysis between the System Engineering standard and the INCOSE Complexity Primer to assess the standard and the nature of complexity in systems. The analysis conducted shows that present descriptions of how complexity create a problem space that is distinctly different to the problem space that can be addressed by present practices. Furthermore, it was found that System Engineering methodology described within the standard will encounter significant challenges in dealing with the attributes of complexity documented in the INCOSE Complexity Primer. Additionally, a crosswalk is conducted between complex systems as describe by the primer and system of systems (SoS) to illicit similarities or differences.

Internet of Things as System of Systems: A Review of Methodologies, Frameworks, Platforms, and Tools

The Internet of Things (IoT) is the latest example of the System of Systems (SoS), demanding for both innovative and evolutionary approaches to tame its multifaceted aspects. Over the years, different IoT methodologies, frameworks, platforms, and tools have been proposed by industry and academia, but the jumbled abundance of such development products have resulted into a high (and disheartening) entry-barrier to IoT system engineering. In this survey, we steer IoT developers by: 1) providing baseline definitions to identify the most suitable class of development products—methodologies, frameworks, platforms, and tools–for their purposes and 2) reviewing seventy relevant products through a comparative and practical approach, based on general SoS engineering features revised in the light of main IoT systems desiderata (i.e., interoperability, scalability, smartness, and autonomy). Indeed, we aim to lessen the confusion related to IoT methodologies, frameworks, platforms, and tools as well as to freeze their current state, for eventually easing the approach towards IoT system engineering.

Ten Views: Towards a Process Meta-Model in a System of Systems Context

Improvement and risk management plans are essential and required in any process lifecycle, particularly when the process is linked to a system of systems (SoS). The first step in the process lifecycle is process modelling. The ISO 9001 Standard recommends the design of improvement and risk plans in the process modelling step. Thus, this paper proposes a process meta-model which takes into account the SoS context and integrates the improvement and risk management processes, based on ISO standards. It also introduces knowledge bases related to improvement and risks in order to ensure continuous improvement of the process and anticipate the malfunctions. The proposed meta-model is an extension of Seven Views, which is a process modelling approach, by three additional views, Risk view, Improvement view, and SoS view.

A Comparison of the System Engineering Standard and INCOSE Complexity Primer

Complexity is frequently used to describe the environment in which systems engineering must work. Relevant publications establish a relationship between complexity and understanding, however, it is questionable whether system engineering methodologies are well suited to deal with complexity and potential lack of understanding. This paper provides an analysis between the System Engineering standard and the INCOSE Complexity Primer to assess the standard and the nature of complexity in systems. The analysis conducted shows that present descriptions of how complexity create a problem space that is distinctly different to the problem space that can be addressed by present practices. Furthermore, it was found that System Engineering methodology described within the standard will encounter significant challenges in dealing with the attributes of complexity documented in the INCOSE Complexity Primer. Additionally, a crosswalk is conducted between complex systems as describe by the primer and system of systems (SoS) to illicit similarities or differences.

A model to discipline autonomy in cyber‐physical systems‐of‐systems and its application

AbstractA cyber‐physical system‐of‐systems (CPSoS) can be defined as a system‐of‐systems (SoS), composed of several operable and autonomous constituent systems (CSs) that are themselves cyber‐physical systems (CPSs). A main challenge in integrating CPSoS to function as a single integrated system is the autonomy of its components, which may result in undesirable, unsecure, or even unsafe situations. In this paper, we advocate that in order to facilitate the integration of CPSs within the overall context of their CPSoS, we may need to adjust their level of autonomy in a way that enables them to perform their activities and avoid undesirable, unsecure , and unsafe situations. Reducing such situations surely contributes to the dependability of the CPSoS. In particular, we propose a novel model‐based approach for modeling and analyzing the autonomy levels of CPSs based on their awareness concerning their operational environment as well as their capability to react in a timely, secure, and safe manner while performing their activities. The model is further described in a UML profile and applied to represent activities for autonomous driving scenarios. Using a driving simulator, we implement such models on a target vehicle, and we show the resulting safety improvement, especially in terms of reduced collisions.

Black-Swan Type Catastrophes and Antifragility/Supra-resilience of Urban Socio-Technical Infrastructures

This paper may be one of the first attempts dealing with the problem of creating, providing and maintaining antifragility of systems of interdependent urban critical infrastructures (CI) in the wake of black-swan type technological, ecological, economic or social catastrophes occurring in a municipality. A synonym is offered to describe antifragility from a positive psychology perspective, formulating the problem as the supraresilience problem. A brief description is given of the developed innovative approach for creating a supraresilient city/region using black-swan catastrophe and the antifragility concepts. Resilience metrics are formulated as well as methods of assessing damage, interdependence of infrastructures and convergent technologies and sciences needed for practical regional resilience and risk management of the system of systems (SoS) of interdependent urban critical infrastructures).

Adding a Detrital Actor to Increase System of System Resilience: A Case Study Test of a Biologically Inspired Design Heuristic to Guide Sociotechnical Network Evolution

AbstractNetworking complex sociotechnical systems into larger Systems of Systems (SoS) typically results in improved performance characteristics including sustainability, efficiency, and productivity. The response, or lack thereof, of many SoS to unexpected constituent system failures undermines their effectiveness in many cases. SoS performance after faults can be improved by improving the SoS’s hard (physical design) or soft (human intervention) resilience. The current approaches to increase resilience are limited due to the cost and necessary of human response increasing non-linearly with SoS scale. The limitations of current approaches require a novel design approach to improve SoS network resilience. We hypothesize that biologically inspired network design can improve SoS resilience. To illustrate this, a systems dynamics model of a Forestry Industry is presented and an optimization search over potential hard and soft resilience approaches is compared to a biologically inspired network improvement. SoS network resilience is measured through the newly developed System of System Resilience Measurement (SoSRM). Our first result provides evidence that biologically inspired network design provides an approach to increase SoS resilience beyond hard and soft resilience improvements alone. Second, this work provides evidence that having a SoS constituent fulfill the ecosystem role of detrital actor increases resilience. Third, this paper documents the first case study using the new SoSRM metric to justify a design decision. Finally, this case study provides a counter-example to the theory that increased sustainability always results in increased resilience. By comparing biologically inspired network redesign and optimized traditional resilience improvements, this paper provides evidence that biologically inspired intervention may be the needed strategy to increase sociotechnical SoS network resilience, improve SoS performance, and overcome the limitations of traditional resilience improvement approaches.

Incremental, Distributed, and Concurrent Service Coordination for Reliable and Deterministic Systems-of-Systems

Systems-of-systems (SoS) are gaining increasing attention for the realization of safety-relevant applications with reliability and real-time requirements, by coordinating autonomous constituent systems from different application areas. For a given application that is initiated at a constituent system, the provision and use of services between constituent systems must be coordinated. This involves identifying constituent systems that can provide the services, optimizing the use of the services driven by extra-functional properties, performing admission control for service provision, reserving resources for provided services, and recursively using services from subcontracted constituent systems to realize service provisions. In this article, new conceptual models with service provisioning for reliable and deterministic SoS applications, as well as, distributed algorithms for the discovery, optimized selection, and admission of service provisions are introduced. The proposed models will result in a two-step admission control algorithm with short- and long-term admissions based on schedulabiliy tests, resulting in service provisions between constituent systems. Furthermore, this article will investigate the integration of cloud resources for the on-demand instantiation of services. The models and the service coordination are evaluated in a use case from the health-care domain, which investigates the execution time and the scalability of the service coordination.

Evaluating the complexity of engineered systems: A framework informed by a user case study

AbstractEvaluating the complexity of an engineered system is challenging for any organization, even more so when operating in a System‐of‐Systems (SoS) context. Here, we analyze one particular decision support tool as an illustratory case study. This tool has been used for several years by Thales Group to evaluate system complexity across a variety of industrial engineering projects. The case study is informed by analysis of semistructured interviews with systems engineering experts within the Thales Group. This analysis reveals a number of positive and negative aspects of (i) the tool itself and (ii) the way in which the tool is embedded operationally within the wider organization. While the first set of issues may be solved by making improvements to the tool itself, informed by further comparative analysis and growing literature on complexity evaluation, the second “embedding challenge” is distinct, seemingly receiving less attention in the literature. In this paper, we focus on addressing this embedding challenge, by introducing a complexity evaluation framework, designed according to a set of principles derived from the case study analysis; namely that any effective complexity evaluation activity should feature collaborative effort toward building an evaluation informed by a shared understanding of contextually relevant complexity factors, iterative (re‐)evaluation over the course of a project, and progressive refinement of the complexity evaluation tools and processes themselves through linking project evaluations to project outcomes via a wider organizational learning cycle. The paper concludes by considering next steps including the challenge of assuring that such a framework is being implemented effectively.

The effect of an individual's education level on their systems skills in the system of systems domain

Today's rapid proliferation of information and technological advancements has led to complex and uncertain modern systems environments. The problems resulting from this increased complexity may surpass engineers’ current capacity to perform effectively within the domain of complex systems. In response to this situation, the concept of Systems Thinking (ST) has been advanced as an aid to building a mental map that offers a robust conceptual understanding to offset the challenges of modern system of systems (SoS) problems. Although there has been some research regarding the effect of age and gender on ST preferences, there is still a lack of studies investigating how an individual's ST skills preferences in system of systems (SoS) domain vary across educational qualifications. In addition, most of the extant literature focuses on one or two measures to assess the individual ST; thus, there is a need to include the full spectrum of ST measures to assess the ST skills preferences of an individual in the domain of complex systems. To address these gaps, this research uses an established ST skills preferences instrument to gauge an individual’s ST skills preferences in the SoS domain based on the educational qualifications. Two hundred and fifty-eight participants with educational qualifications ranging from non-degree to graduate degree participated in the research. The analysis of the responses was performed by a post-hoc test to show which groups differ significantly. From the results obtained through aggregate individual responses, we conclude that each group (i.e bachelor, masters and phD), possesses a different ST skills preference profile on average, and the educational qualifications in the SoS environment has a moderation impact on individuals’ system skills preferences.

SApHESIA: An agent-based model and a criticality-based heuristic for cooperatively coupling SoSs

Abstract Problems to solve nowadays have never been so complex and are continuously increasing in complexity. In this context Systems of Systems (SoS) may be a solution but the study of such systems is far from over. An SoS is a complex system characterized by the particular nature of its components: the latter, which are systems, tend to be managerially and operationally independent as well as geographically distributed. This specific characterization led to re-think research fields of classic systems engineering, such as definition, taxonomy, modeling, architecting, etc. SoS architecting focuses on the way independent components of an SoS can be dynamically structured and can autonomously and efficiently modify their interactions in order to fulfill the goal of the SoS and to cope with the high dynamics of the environment. This paper contributes to the multi-agent and SoS research fields by proposing a new generic SoS model called SApHESIA which considers the SoS main characteristics found in the literature and extends the notion of environment and interactions between component systems. It also proposes a new SoS architecting procedure based on the Adaptive Multi-Agent System (AMAS) approach that advocates full cooperation between all the components of the SoS through the concept of criticality. This criticality is a measure, local to each component, expressing its difficulties to reach its local goals. In this procedure, the SoS architecture evolves to self-adapt to the dynamics of the environment in which it is plunged, while considering the respective local goals of its components. An instantiation of SApHESIA to two distinct cases studies from different domains (logistics and exploratory missions) is done to obtain two SoSs. These two SoS are then coupled to form a new SoS at an upper level. Evaluations of these SoSs show that their cooperation make each of them more efficient.

Detection Effectiveness Estimation Based on Multi-Angle Data and Visualization Analysis

In intelligent confrontation games, how to estimate the detection effectiveness of the early-warning detection (EWD) system of systems (SoS) is the most important issue that has been studied in hopes of a breakthrough for the long time. The conventional approaches to effectiveness estimation have been reductionism or the linear estimation methods, which are not suitable for the estimation of the effectiveness of EWD SoS. Effectiveness estimation methods and ideas based on complex networks have been proposed and studied, which can inspire that the logic relationship in the SoS can be analyzed by using the network thoughts. As a development of some research based on the Data mode, data and visualization analysis methods have been proposed. In these approaches, the multi-angle data and visualization analysis methods can be utilized to directly show some significant relationships in the SoS from the different aspects, especially from different angles of sight. These statistics and suggested results can be employed to analyze the situation of SoS, so they have potentially important capabilities in terms of the estimation of EWD SoS. Therefore, in this paper, these new ideas are introduced into the study and solution of the problem of the detection effectiveness estimation of EWD SoS. On the basis that the running characteristics of the detecting work of the EWD SoS are described, the data method and idea with multi-angles for EWD SoS are proposed and discussed, and the visualization analysis method and ideas about EWD SoS are suggested and analyzed. Furthermore, a typical application is employed to estimate the detection effectiveness of EWD SoS, based on the data and visualization analysis methods stated in this paper. As the results of the estimate are generally consistent with the actual situation, the validity of the proposed methods is considered proven. The main work in this paper can provide new ideas on the study of the issue of the detection effectiveness estimation of EWD SoS, and it also helpful for SoS analysis and other estimations of effectiveness.

Understandable Capacity Level Assessment Method for Networking Information-Centric System-of-Systems Interoperability

According to the characteristics of the networking information-centric system-of-systems, starting from the understanding ability of the mutual understanding subjects and the information sharing degree of the mutual understanding objects, this paper analyzes the influencing factors of mutual understanding of networking information-centric system-of-systems, extracts four evaluation attributes of education, situation, decision-making and control, describes the selection process of four evaluation attributes, analyzes the factors that affect the mutual understanding level of the networking information-centric system-of-systems in each attribute field, constructs the mutual understanding maturity model of the networking information-centric system-of-systems, analyzes the basic characteristics of each grade, constructs the mutual understanding grade model of the networking information-centric system-of-systems, analyzes the symbolic characteristics of each attribute corresponding to each grade, and puts forward the mutual understanding evaluation method of the networking information-centric system-of-systems, which provides guidance for measuring the ability of the networking information-centric system-of-systems to achieve information advantages and decision-making advantages.

Systems of systems ontology in practice

AbstractThis paper explores possibilities for collaboration between two companies that share interest in a System of Systems (SoS). Although traditional architectural frameworks and standards are applicable, there has been little work presented of how they can be used for collaboration by a practician. As a response to harmonize use of words for an SoS in relationship to standardized set of definitions an INCOSE Work Group project developed a proposal for an ontology that could support collaboration in the context of directed SoS and acknowledged SoS. This ontology is evaluated in the paper, first by a mapping of terms used in product development to test the ontology terms. Then the ontology is further explored with an example of how it could be used in architecture work in relation to directed SoS, specifically from a system safety aspect.

Towards an Ontology for Collaboration in System of Systems Context

AbstractThere is considerable number of architectural frameworks and standards with many pertinent definitions of concepts that are often not compatible with each other, hindering collaboration, especially in the context of System of Systems (SoS). To address this issue, we propose an ontology for SoS that uses Object Process Methodology (OPM) ISO 19450 to facilitate collaboration among organizations with focus on safety aspects. The current effort focuses on the foundational extended taxonomy that uses a minimal set of terms to model system‐ and SoS‐related concepts and relations among them to streamline collaboration among involved SoS stakeholders, with focus on safety. The ontology is illustrated through an example of a self‐parking facility.

Towards a Unified Approach to System‐of‐Systems Risk Analysis Based on Systems Theory

AbstractIn systems‐of‐systems (SoS), trustworthiness is a key concern, which includes operational risks such as safety, security, and privacy. These are particularly challenging to achieve in an SoS, due to the shared responsibility among independent constituent systems. This paper investigates a unified approach based on systems thinking for analyzing risks in SoS. Having a common framework is important, since many risk areas are related and affect each other. The paper also discusses how traditional static risk analysis can be complemented by dynamic techniques that collect data over time to fuel SoS evolution with respect to risk reduction.

Case Study: Achieving System Integration through Interoperability in a large System of Systems (SoS)

AbstractThis paper provides a case study on system of systems engineering (SoSE) being performed in a multi‐billion‐dollar program – the California High‐Speed Rail System – viewed from the systems integration perspective. The paper discusses why the subject program of projects (PoP) can be viewed as a system of systems (SoS), identifies the SoSE challenges faced, describes the SoSE activities performed, and summarizes the achieved outcomes and conclusions as of today.Specific SoSE challenges discussed include SoS authority, leadership, architecting, collaboration, integration, and emergence. The paper reviews how decision‐making in independently operated and managed constituent systems (projects) resulted in unanticipated SoS emergent behavior, which is one of the key challenges in the engineering of SoS.The paper further discusses the performed SoSE activities, including an international best practice review, the tailoring of SoSE to the specific SoSE challenges, and provides examples where SoSE principles are being applied to perform successful SoS integration.

Exploring Health Information Exchange Through a System of Systems Framework

Clinical decisions require timely availability of holistic patient health information including clinical, demographic, behavioral, and socioeconomic risk factors. Health information exchanges (HIEs) help bridge the technical and organizational divides between disparate Electronic health records (EHR) systems and facilitate the sharing of health information between providers and between patients and providers through collaborative governance, secure protocols, and interoperable standards. HIEs come in many varieties and can be highly complex, both technically and organizationally. This conceptual paper adopts a system of systems (SoS) framework from the systems engineering discipline to analyze and break down the complexity of HIEs. The mnemonic nature of the five characteristics of the Boardman and Sauser SoS Model (A for Autonomy, B for Belonging, C for Connectivity, D for Diversity, and E for Emergence) makes it easier to understand the intricacy of HIEs and helps remove the barriers to effective use of HIEs for care coordination, patient safety, and patient-centered care quality.

Achieving System‐of‐Systems Interoperability Levels Using Linked Data and Ontologies

AbstractInteroperability is a key concern in systems‐of‐systems (SoS). Numerous frameworks have been proposed to deal with this, but they are generally on a high level and do not provide specific guidance for technical implementation. However, in the context of simulation, the Levels of Conceptual Interoperability Model (LCIM) has been proposed. Also, the semantic web initiative has been introduced to provide description logic information to web pages. This paper investigates how these two concepts can be combined into a general approach for SoS interoperability. It also expands on the LCIM model by providing more details about the world models of a system and its content on the higher levels of interoperability. The combination is illustrated using an example of autonomous vehicles, and experiences from other applications are also discussed.