The development of large-scale software intensive systems such as cyber-physical systems (CPS) involves many different professionals, in particular engineers from several engineering disciplines. \emph{Boundary objects} are commonly used in this context to facilitate the interactions between engineers. These are artefacts that hold different meaning to several groups and serve as a means of translating information between them. This paper presents a scoping review investigating the current state of the boundary object concept, and factors that can affect the effectiveness of boundary objects, within the discourse on the development of complex CPS. The results contribute to theory by selecting a promising approach to overcome the overextension of the concept, and using this approach to leverage on two orthogonal aspects of boundary objects. The latter reveals a two-dimensional continuum along which boundary objects are more or less (a) \emph{transparent} or \emph{opaque}, and (b) a \emph{support} or \emph{limiter} on human activity. Furthermore, the results contribute to management concerns of systems and software development practice by considering which contextual factors that influence the efficacy of boundary objects used for complex CPS development. The findings call for practitioners to put more effort into understanding culture as an important contextual factor that either enables or acts as a barrier to the continued success of boundary objects. In particular, many boundary objects are currently evolving into ‘intelligent boundary objects’ as engineering tools increasingly integrate (generative) artificial intelligence to support human augmentation. This study suggests that the shared meanings, values and assumptions of those that develop these tools must be made transparent in the boundary objects generated by them, lest the ability of engineers to make well-informed, unbiased decisions is compromised.

Cyber-Physical Systems (CPS) have progressed far beyond their origins in embedded control, evolving into large-scale software intensive systems that play an important role in modern society. By tightly integrating computation, sensing, control, and communication, CPS drive innovation across domains such as transportation, energy, healthcare, and industrial automation. As these systems become increasingly intelligent and interactive, often incorporating artificial intelligence (AI) and engaging dynamically with human users and their environments, new concerns arise regarding their trustworthiness. These concerns extend beyond traditional notions of dependability to include ethical considerations such as transparency, fairness, and accountability. As a result, ensuring classical dependability aspects while also addressing ethical dimensions of AI such as transparency, fairness, and accountability, is not only a technical challenge but also a socio-technical imperative. Consequently, the development of CPS requires interdisciplinary collaboration among stakeholders with diverse expertise. 

As the current development of CPS increasingly depends on interdisciplinary collaboration, the urgency of conducting effective co-engineering practices becomes ever more essential. However, this co-engineering practice is frequently challenged by knowledge boundaries stemming from differences in disciplinary languages, method, and interests. These boundaries can lead to misalignment and conflicting interpretations that disrupt co-engineering practices among the stakeholders involved. Addressing these challenges is a socio-technical endeavour that requires the integration of technical factors and social factors, particularly those that enable effective collaboration across disciplinary and organizational boundaries.

The concept of boundary objects provides a useful lens for tackling these issues. Originally introduced in the sociology, boundary objects are artifacts that are flexible enough to be interpreted differently across social worlds, yet robust enough to maintain a coherent identity. For example, they function as mediating structures that help align diverse perspectives, coordinate efforts across disciplinary boundaries, and facilitate negotiation of competing interests. In the engineering context, boundary objects may take the form of reference architectures that allow stakeholders to understand one another without requiring full consensus on meanings or methods. This combination of being flexible enough to adapt to local needs and constraints, while remaining stable enough to maintain a shared identity across different stakeholder groups, makes boundary objects particularly valuable for navigating the complexity and uncertainty of co-engineering practices.

This thesis investigates how reference architectures function as boundary objects that support co-engineering in the development of trustworthy CPS. Drawing on boundary object theory, it conceptualizes reference architectures as artifacts that enable translation across knowledge domains, mediate semantic and pragmatic boundaries, and provide a shared platform for e.g., negotiating trade-offs, especially those related to trustworthiness aspects and requirements. The research combines theoretical analysis with empirical studies in CPS domains such as automotive and railway, exploring how factor such as knowledge stickiness and organizational factor such as power dynamics within the organization shape the interpretation and utilization of reference architectures as boundary objects that support co-engineering practices.

The thesis makes three main contributions. First, it clarifies the theoretical understanding of boundary objects within the discourse of CPS development by situating reference architectures as socio-technical mediators of collaboration rather than merely technical design templates. Second, it offers empirical insights into how contextual factors influence the use and effectiveness of reference architectures in supporting the co-engineering in the development of trustworthy CPS. Third, it develops and evaluates an architectural framework that supports co-engineering practices by providing methods to help stakeholders navigate knowledge boundaries during the development of trustworthy CPS.

Cyberfysiska system (CPS) har utvecklats långt bortom sitt ursprung i inbyggd styrning och utvecklats till storskaliga mjukvaruintensiva system som spelar en viktig roll i det moderna samhället. Genom att tätt integrera beräkning, sensorer, styrning och kommunikation driver CPS innovation inom områden som transport, energi, sjukvård och industriell automation. I takt med att dessa system blir alltmer intelligenta och interaktiva, ofta med artificiell intelligens (AI) och dynamiskt interagerar med mänskliga användare och deras miljöer, uppstår nya farhågor kring deras tillförlitlighet. Dessa farhågor sträcker sig bortom traditionella föreställningar om tillförlitlighet och inkluderar etiska överväganden som transparens, rättvisa och ansvarsskyldighet. Som ett resultat är det inte bara en teknisk utmaning utan också ett sociotekniskt imperativ att säkerställa klassiska tillförlitlighetsaspekter samtidigt som man tar itu med etiska dimensioner av AI, såsom transparens, rättvisa och ansvarsskyldighet. Följaktligen kräver utvecklingen av CPS tvärvetenskapligt samarbete mellan intressenter med olika expertis.

Konceptet med gränsobjekt ger en användbar lins för att ta itu med dessa frågor. Ursprungligen introducerades gränsobjekt inom sociologin och är artefakter som är tillräckligt flexibla för att tolkas olika över sociala världar, men ändå tillräckligt robusta för att upprätthålla en sammanhängande identitet. De fungerar till exempel som förmedlande strukturer som hjälper till att anpassa olika perspektiv, koordinera insatser över disciplinära gränser och underlätta förhandlingar om konkurrerande intressen. I ingenjörskontexten kan gränsobjekt ta formen av referensarkitekturer som gör det möjligt för intressenter att förstå varandra utan att kräva fullständig konsensus om betydelser eller metoder. Denna kombination av att vara tillräckligt flexibel för att anpassa sig till lokala behov och begränsningar, samtidigt som de förblir tillräckligt stabila för att upprätthålla en gemensam identitet mellan olika intressentgrupper, gör gränsobjekt särskilt värdefulla för att navigera komplexiteten och osäkerheten i samutvecklingsmetoder.

Denna avhandling undersöker hur referensarkitekturer fungerar som gränsobjekt som stöder samutveckling i utvecklingen av tillförlitliga CPS. Med utgångspunkt i gränsobjektteorin konceptualiserar den referensarkitekturer som artefakter som möjliggör översättning över kunskapsområden, förmedlar semantiska och pragmatiska gränser och tillhandahåller en gemensam plattform för t.ex. att förhandla om avvägningar, särskilt de som är relaterade till tillförlitlighetsaspekter och krav. Forskningen kombinerar teoretisk analys med empiriska studier inom CPS-domäner som fordonsindustrin och järnvägen, och utforskar hur faktorer som kunskapsfasthet och organisatoriska faktorer som maktdynamik inom organisationen formar tolkningen och användningen av referensarkitekturer som gränsobjekt som stöder samutvecklingsmetoder.

Avhandlingen ger tre huvudsakliga bidrag. För det första klargör den den teoretiska förståelsen av gränsobjekt inom diskursen kring CPS-utveckling genom att placera referensarkitekturer som sociotekniska medlare för samarbete snarare än bara tekniska designmallar. För det andra erbjuder den empiriska insikter i hur kontextuella faktorer påverkar användningen och effektiviteten av referensarkitekturer för att stödja samutveckling i utvecklingen av tillförlitliga CPS. För det tredje utvecklar och utvärderar den ett arkitektoniskt ramverk som stöder samutvecklingsmetoder genom att tillhandahålla metoder för att hjälpa intressenter att navigera kunskapsgränser under utvecklingen av tillförlitliga CPS.

Best practices in sustainability engineering have gained traction in recent years, reflecting the global urgency to integrate sustainability principles into product development. However, the impact of sustainability standardization on engineering is still weak. This study investigates whether a transdisciplinary approach is possible, i.e., if sustainability initiatives could build upon the groundwork laid by efforts to ensure another system-wide property – safety. Insights were elicited on entities and structures in product and process innovation communities through semi-structured interviews. Using an abductive approach these entities and structures are revealed not only as drivers of innovation, but also as what defines (safety and sustainability) practice that can later make its way into standards. This study thus augments established theory considering innovation systems, shifting the perspective to what limits the evolution of products and processes to contribute a framework for a systemic understanding of standardization efforts. By utilizing this framework, the comparatively weak infrastructure of sustainability throughout engineering activities, and the importance of intermediary organisations to sustainability standardization, are identified. Based on these observations the study argues for the need to, as safety engineering does, reinforce sustainability practice by requiring engineers to construct a logical case for sustainability throughout product development and manufacturing activities.

Context:The complexity of large-scale, software-intensive systems demands collaborative efforts across engineering disciplines to assure that all system properties are correctly implemented. Effective communication and knowledge sharing among the involved engineering are critical for fostering this collaboration. As a result, engineering artifacts, such as reference architectures, play a key role as boundary objects—shared objects used by different communities to reach a mutual understanding.Objective:This study aimed to understand how engineer should utilize reference architectures as boundary objects, and explored the challenges in using them in the co-engineering of system properties.Methodology and Methods:Semi-structured interviews were conducted with 10 experts from two engineering disciplines focusing on system properties of particular importance to contemporary large-scale software-intensive systems development. To analyze the data, an abductive thematic analysis approach was used.Results:Reference architectures can be used as promoters of synergy, change, and learning by the engineers involved in the co-engineering of system properties. However, related challenges with regard to organizational contexts were identified. These findings underscore the need for further investigations into the relationship between the role of reference architectures, power, and organizational theory.

Developing trustworthy cyber-physical systems (CPS) demands cross-boundary collaboration among stakeholders with diverse disciplinary backgrounds, often creating challenges in crossing knowledge boundaries. Boundary objects, i.e., artifacts that enable shared understanding across domains, can help mitigate these challenges. This study examines the trustworthiness framework (T-Framework), as a boundary object, to support cross-boundary collaboration in trustworthy CPS development. Specifically, it addresses two research questions: (1) To what extent does the T-Framework, as a boundary object, support the crossing of knowledge boundaries in the development of trustworthy CPS? and (2) How can the T-Framework and its associated method be extended to address any identified gaps? Drawing on theories of knowledge boundaries and boundary objects, the study empirically evaluates the T-Framework through focus groups with CPS practitioners from academia and industry. Insights from these focus group sessions inform refinement of the T-Framework and its method to address identified gaps in its capability to support cross-boundary collaboration. In addition, the findings highlight the importance of incorporating structured mechanisms into both the design and utilization of architectural frameworks to promote shared understanding, address conceptual misalignment, and balance stakeholder influence during cross-boundary collaboration in the development of trustworthy CPS.

The development of large-scale software-intensive systems, such as cyber-physical systems (CPS), is increasingly complex, influenced by both technical and human aspects. Technically, critical system properties like safety and cybersecurity must be addressed from the early development stages, as these properties are interrelated and impact one another. Managing them requires cross-disciplinary collaborations among diverse engineers, i.e., co-engineering practice. Reference architectures are often viewed as boundary objects, i.e., objects used by diverse groups to reach common ground, to facilitate these co-engineering practices. However, the effectiveness of reference architectures as boundary objects in fostering co-engineering practices can be shaped by power dynamics within and among teams. This study investigates how different types of power held by engineers influence their preferences for specific types of reference architectures. A mixed-method approach was employed, beginning with quantitative data collection through surveys distributed to engineers and key stakeholders, such as project managers involved in co-engineering safety and cybersecurity.

This study provides an evaluation of an architecture framework intended to support stakeholders in realizing trustworthy cyber-physical systems (CPS), referred to as the T-Framework. The framework explicitly addresses CPS complexity, including the fact that multiple trustworthiness aspects will need to be considered for contemporary CPS, from classical dependability aspects to ethical concerns involving artificial intelligence. In addition, this study also investigates the problems that are repeatedly encountered by the stakeholders involved in realizing trustworthy CPS. To achieve the goals of the study, the boundary object and knowledge boundary concepts from social sciences were used. These concepts are useful tools to examine how various involved stakeholders can cooperate on a project through the utilization of objects, even though they have different perspectives and conflicting interests. Focus groups were used as the methodological approach to gather feedback from various experts in CPS from industry and academia. Findings show that stakeholders repeatedly encounter problems when making trade-offs between trustworthiness attributes and system aspects, dealing with prioritization, and making final decisions. The findings further show that the T-Framework can potentially guide stakeholders in addressing these problems as a boundary object. Furthermore, based on the feedback from the participants, several aspects for improvements or additional consideration in the T-Framework were identified, including clarifications regarding the framework workflow and terminology.

Research background: Digital ecosystems in Europe are heterogenous organizations involving different economies, industries, and contexts. Among them, Digital Innovation Hubs (DIHs) are considered a policy-driven organization fostered by the European Commission to push companies’ digital transition through a wide portfolio of supporting services.

Purpose of the article: There are DIHs existing in all European economies, but literature needs more precise indications about their status and nature. The purpose is to study a distribution of DIHs and differences in portfolios of DIHs’ services across European economies. Therefore, the paper wants to deliver more precise data on effects on national and European policies. This is required to define their final role and scope in the complex dynamics of the digital transition, depending on regional context and heterogeneity of industries.

Methods: Data on 38 economies was collected from the S3 platform (on both existing and in preparation DIHs) and further verified by native speaking researchers using manual web scrapping of websites of DIHs identified from S3. To find potential similarities of digital ecosystems in different economies as emanated by the existence of DIHs, clusterization (Ward’s method and Euclidean distances) was applied according to the services offered. Economies were clustered according to the number of DIHs and the spread of DIHs intensity in different cities. The results were further analyzed according to the scope of the provided services.

Findings & value added: The applied clustering classified European economies in four different sets, according to the types of services offered by the DIHs. These sets are expression of the different digitalization statuses and strategies of the selected economies and, as such, the services a company can benefit from in a specific economy. Potential development-related reasons behind the data-driven clustering are then conjectured and reported, to guide companies and policy makers in their digitalization strategies.

Edge computing is projected to have profound implications in the coming decades, proposed to provide solutions for applications such as augmented reality, predictive functionalities, and collaborative Cyber-Physical Systems (CPS). For such applications, edge computing addresses the new computational needs, as well as privacy, availability, and real-time constraints, by providing local high-performance computing capabilities to deal with the limitations and constraints of cloud and embedded systems. Edge computing is today driven by strong market forces stemming from IT/cloud, telecom, and networking - with corresponding multiple interpretations of ”edge computing” (e.g. device edge, network edge, distributed cloud, etc.). Considering the strong drivers for edge-computing and the relative novelty of the field, it becomes important to understand the specific requirements and characteristics of edge-based CPS, and to ensure that research is guided adequately, e.g. avoiding specific gaps.

Our interests lie in the applications of edge computing as part of CPS, where several properties (or attributes) of trustworthiness, including safety, security, and predictability/availability are of particular concern, each facing challenges for the introduction of edge-based CPS. We present the results of a systematic mapping study, a kind of systematic literature survey, investigating the use of edge computing for CPS with a special emphasis on trustworthiness. The main contributions of this study are a detailed description of the current research efforts in edge-based CPS and the identification and discussion of trends and research gaps. The results show that the main body of research in edge-based CPS only to a very limited extent consider key attributes of system trustworthiness, despite many efforts referring to critical CPS and applications like intelligent transportation. More research and industrial efforts will be needed on aspects of trustworthiness of future edge-based CPS including their experimental evaluation. Such research needs to consider the multiple interrelated attributes of trustworthiness including safety, security, and predictability, and new methodologies and architectures to address them. It is further important to provide bridges and collaboration between edge computing and CPS disciplines.

Scenario-based approaches have been receiving a huge amount of attention in research and engineering of automated driving systems. Due to the complexity and uncertainty of the driving environment, and the complexity of the driving task itself, the number of possible driving scenarios that an Automated Driving System or Advanced Driving-Assistance System may encounter is virtually infinite. Therefore it is essential to be able to reason about the identification of scenarios and in particular critical ones that may impose unacceptable risk if not considered. Critical scenarios are particularly important to support design, verification and validation efforts, and as a basis for a safety case. In this paper, we present the results of a systematic mapping study in the context of autonomous driving. The main contributions are: (i) introducing a comprehensive taxonomy for critical scenario identification methods; (ii) giving an overview of the state-of-the-art research based on the taxonomy encompassing 86 papers between 2017 and 2020; and (iii) identifying open issues and directions for further research. The provided taxonomy comprises three main perspectives encompassing the problem definition (the why), the solution (the methods to derive scenarios), and the assessment of the established scenarios. In addition, we discuss open research issues considering the perspectives of coverage, practicability, and scenario space explosion.