Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references.

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2004. / Dr. Michael Hunter, Committee Member ; Dr. Alexander M. Puzrin, Committee Member ; Dr. Nelson Baker, Committee Chair. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 156-166.

Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004. / Cover title. Includes bibliographical references (p. 129-134). Also available online from the MIT website (http://www.mit.edu/).

Background: In developing and maintaining a large-scale system-of-systems (SoS), interface coordination & control (ICC) among interdependent subsystems is crucial for evolving individual subsystems and the overall SoS. However, the available literature offers little or no support to guide ICC in practice. Objectives: To describe how ICC can be done in the context of a large-scale SoS.We aimed to explore and analyze Ericsson’s (an example of a typical large-scaleSoS) current process and practices. To identify any limitations of the process, we investigated the challenges faced by practitioners regarding ICC, their reasons, and implications. Furthermore, we researched and proposed improvement possibilities to overcome the identified challenges. Method: We conducted a case study research and used observations, interviews, focus groups, and archival analysis for data collection. We used coding techniques from grounded theory and descriptive statistics to analyze qualitative and quantitative data, respectively. Moreover, the tabulation technique was employed to identify improvement opportunities. Results: We found that ICC is part of an overall technical coordination process. ICC is implemented through a recurrent cycle of activities. It brings together stakeholders to present upcoming changes, discuss their impact, and plan mitigation strategies. The outcome of ICC is a list of agreed-upon changes, impacted subsystems, and version numbers of interacting objects for the next release. We categorised the identified challenges in three groups: "people & subsystems", "tools, artifacts & technique", and "organization & management". These challenges impeded the effectiveness of the ICC process, quality of the SoS, and overall efficiency of the ICC and development process. Need for training, tool support, and stronger governance were identified as possible improvements to address multiple categories of identified challenges. Conclusion: The studied ICC process is well adapted for the large-scale SoS context. It is reasonably effective in minimizing the impact of evolving subsystems on the functioning and quality of SoS (as evident from the defect report analysis in this thesis). It also helps in cost-saving through early detection of compatibility-related issues. This thesis describes an ICC process used in practice, a novel contribution to the software configuration management (SCM) literature. In addition, companies in similar contexts can use the ICC description. The described ICC process is generalizableas as it is agnostic of the underlying development technologies used in a company.

yes / This paper presents a structured approach for systems requirements analysis that integrates use case modelling with a coherent flows based approach for describing interface exchanges based on the Interface Analysis Template. The approach is discussed in the context of current frameworks for requirements elicitation from the engineering design and systems engineering domains, and it is illustrated with an automotive case study. This illustrates the strength of the framework to support structured multi-domain and multi-disciplinary analysis of requirements for complex systems.

Un Système de Systèmes (SdS ou System of Systems - SoS) est un système complexe résultant de l'assemblage de composants existant ou à créer, de nature hétérogène (e.g. des systèmes techniques ou socio techniques appelés sous-systèmes, dispositifs techniques, acteurs ou organisations, ou encore des infrastructures plus ou moins complexes pouvant être perçues comme des SdS). Cet assemblage est nécessaire à ces composants pour agir et interagir avec d'autres composants afin de réaliser une mission commune, éventuellement limitée dans le temps et qu'aucun de ces composants ne pourrait réaliser seul. De fait, un SdS possède des caractéristiques particulières comme l'hétérogénéité, la possible émergence de propriétés et de comportements durant les interactions entre les composants et à leurs interfaces, la préservation de l'autonomie managériale et opérationnelle de ces composants, la répartition géographique de ces composants, un cycle de vie particulier, etc. L'Ingénierie Système (IS ou Systems Engineering - SE) propose et promeut un ensemble de concepts, de processus maintenant standardisés, l'usage incontournable de modèles (on parle alors de Model Based Systems Engineering – MBSE) et de bonnes pratiques pour concevoir et réaliser des systèmes complexes. Du fait de ses caractéristiques particulières, la conception et le développement d'un SdS (SoS Engineering - SoSE) est elle-même particulière même si elle emprunte à l'IS nombre de traits communs. En effet, le choix et l'assemblage des composants, leurs besoins en termes d'interfaces pour faciliter leurs interactions entre eux et avec l'environnement du SdS, les propriétés et comportements émergents entres autres caractéristiques, impliquent des efforts de la part des personnes en charge d'un SdS. Il faut alors, pour les aider dans leurs tâches, conceptualiser et développer des langages, méthodes et outils supports. Le SoSE a en effet des besoins particuliers de modélisation, de vérification, de validation de modèles. Il nécessite également de disposer de moyens de simulation et d'évaluation du comportement global du SdS et de ses propriétés, par exemple, lorsqu'il doit faire face à des événements redoutés (e.g. ajout, modification ou retrait d'un composants, évolution de la mission, etc.). Le but est que ces personnes puissent progresser en confiance et leur donner les moyens de fournir des modèles de SdS avec lesquels l'analyse des propriétés du SdS devient possible, avant même d'alimenter les activités de décision et d'optimisation en cours de conception du SdS. Ce travail s'intéresse à une propriété importante pour les SdS et leurs composants : l'interopérabilité. Elle est vue ici comme une exigence sommative des capacités et des capabilités des composants à être et rester compatibles, à inter opérer efficacement, à rester autonome pendant l'interaction et à la réversibilité de la relation d'interaction lorsque celle-ci s'achève. L'interopérabilité garantit donc ou, à défaut, maximise la capacité d'un composant à travailler sans perte et harmonieusement avec un autre composant, dans différentes situations et avec un niveau de performance attendu, tout en respectant un ensemble d'autres exigences venant des parties prenantes impliquées ou concernées par le SdS visé.Cette thèse consiste à formaliser et à développer une méthode pour accompagner la modélisation, la vérification de modèles et l'analyse de l'interopérabilité dans un SdS. En conséquence elle repose sur 1) un ensemble de concepts et de relations entre ces concepts pour décrire un SdS et la propriété d'interopérabilité, 2) des langages spécifiques de modélisation (DSML) pour manipuler ces concepts et relations et donc créer des « modèles » de SdS, 3) d'un processus opératoire et 4) d'outils de modélisation, de vérification des modèles, de simulation du comportement et d'évaluation de l'interopérabilité et de son influence sur la performance, la stabilité et l'intégrité du SdS en cours de fonctionnement. / A System of Systems (SdS) is a complex system which is seen as a group of, in most cases, existing and heterogeneous entities (e.g. technical systems or socio-technical called subsystems, actors or organizations or even complex infrastructures that can be considered as SoS) assembled together in order to interact, during a timeframe to produce some kind of capabilities, products or services and to achieve a global mission that a system alone cannot fulfill. Moreover, the SoS has some particular characteristics such as: Operational Independence and Managerial Independence (autonomy), Evolutionary Development, Emergent Behavior, Geographic distribution, Connectivity and Diversity etc. The systems engineering (SE) provides and promotes a set of concepts, principles, processes, standards, an essential use of models (Model Based Systems Engineering - MBSE)and a good practice to design and conduct complex systems. However, even if the System of Systems Engineering (SoSE) shares some common features with the SE, SoS characteristics, assembling, interfacing and interactions between its entities, induce an additional effort, required from the persons responsible of the SoS, over the SE. Therefore, and in order to help these persons in their tasks, it is necessary to conceptualize and develop languages, methods and tolls supports. The SoSE has special needs in terms of modeling and models' verification and validation. Moreover, it requires to have means to simulate and evaluate the global behavior of the SoS and its properties, for example, when it has to face dangerous events (e.g. adding, removing or modifying a component, mission's evolution etc.). The aim is to help designers and engineers to progress in confidence by giving them the means to have SoS models with which the analysis of the SoS properties becomes possible. In this work, a particular attention is given to an important property of the SoS and its components: the interoperability. It is seen here as a summative requirement of components capacities and capabilities to remain compatible, to interoperate and to remain autonomous during the interactions and reversible after it. The interoperability guarantees or, by default, maximizes the capacity of a component to work, harmoniously and without any loss, with another component, in various situations and with an expected level of performance while respecting a set of requirements (stakeholders involved or concerned by the SoS).This thesis consists in formalizing and developing a method to support modeling, model's verification and the analysis of the interoperability in a SoS. Therefore, it is based on 1) a set of concepts and relationships between these concepts to describe a SoS as well as the interoperability property, 2) Domain Specific Modeling Languages (DSMLs) to manipulate these concepts and relationships and thus creating a SoS' model, 3) an operating process and 4) a modeling and verification tools, simulating behavior and evaluation of the interoperability and its impact on the SoS performance, stability and integrity while it is operating.

Society is challenging systems engineers by demanding increasingly complex and integrated IT systems (Northrop et al., 2006; RAE, 2004) e.g. integrated enterprise resource planning systems, integrated healthcare systems and business critical services provisioned using cloud based resources. These types of IT system are often systems-of-systems (SoS). That is to say they are composed of multiple systems that are operated and managed by independent parties and are distributed across multiple organisational boundaries, geographies or legal jurisdictions (Maier, 1998). SoS are notorious for becoming problematic due to interconnected technical and social issues. Practitioners claim that they are ill equipped to deal with the sociotechnical challenges posed by system-of-systems. One of these challenges is to identify the socio-technical threats associated with building, operating and managing systems whose parts are distributed across organisational boundaries. Another is how to troubleshoot these systems when they exhibit undesirable behaviour. This thesis aims to provide a modelling abstraction and an extensible technique that enables practitioners to identify socio-technical threats prior to implementation and troubleshoot SoS post-implementation. This thesis evaluates existing modelling abstractions for their suitability to represent SoS and suggests that an agent-responsibility based modelling abstraction may provide a practical and scalable way of representing SoS for socio-technical threat identification and troubleshooting. The practicality and scalability of the abstraction is explored through the use of case studies that motivate the extension of existing responsibility-based techniques so that new classes of system (coalitions-of-systems) and new classes of threat (agent-related threats) may be analysed. This thesis concludes that the notion of ‘responsibility' is a promising abstraction for representing and analysing systems that are composed of parts that are independently managed and maintained by agents spanning multiple organisational boundaries e.g. systems-of-systems, enterprise-scale systems.

This article considers emergence in the context of systems of systems, examining the earlier proposed tri-layered architecture in some depth. In contrast with healthcare reform, a social media phenomenon, the emergence of topics in the Twitter user community, is shown not to satisfy a critical condition of the architecture. Nevertheless, detection of topic emergence is shown to offer insights into the design of Emergence Behavior Observers.