Dr.-Ing.

Kuhn, Thomas

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  • Publication
    Enabling SMEs to Industry 4.0 Using the BaSyx Middleware: A Case Study
    ( 2021)
    Kannoth, Subash
    ;
    Hermann, Jesko
    ;
    Damm, Markus
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    Rübel, Pascal
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    Rusin, Dimitri
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    Jacobi, Malte
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    Mittelsdorf, Björn
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    Kuhn, Thomas
    ;
    Antonino, Pablo Oliveira
    Industry 4.0 (I4.0) concepts evolve the current industrial processes towards directly connecting shopfloor machines to systems from different layers of the Automation Pyramid, such as Enterprise Resource Planning (ERP) or Manufacturing Execution Systems (MES). Companies introducing I4.0 concepts aim at (i) facilitating changeable production systems in order to quickly react to customer inquiries such that even lot-size one becomes feasible and (ii) having a holistic view of the different parameters of a production process. Enabling these calls for accessing the different systems of the Automation Pyramid, which is hard to achieve in traditional production systems without technical changes consuming time, effort and budget, mainly due to the lack of standardization, heterogeneous protocols, and the lack of proper interfaces among the systems of the Automation Pyramid. This challenge is greater in small and medium-size enterprises (SMEs) due to economic reasons or lack access to personnel with a skill set encompassing all the levels of the Automation Pyramid. I4.0-based concepts are built according to the Service-Oriented Architecture principle to enable peer-to-peer communication of systems from each layer of the Automation Pyramid. The service-oriented middleware architecture Eclipse BaSyx 4.0 implements SOA and other I4.0 concepts such as Digital Twins, and has been instantiated in German companies of different sizes. In this paper, we present two use cases focusing on of adoption of Eclipse BaSyx in two German SMEs and show how this enables the adoption of I4.0 concepts with improved time, effort and budget.
  • Publication
    Architecture Blueprint Enabling Distributed Digital Twins
    ( 2021)
    Schnicke, Frank
    ;
    Espen, Daniel
    ;
    Antonino, Pablo Oliveira
    ;
    Kuhn, Thomas
    Mass production today is optimized for large lot sizes, and changes to industrial production lines are effort-intense, time-consuming, and costly. The fourth industrial revolution, Industry 4.0 (I4.0), aims at reducing the effort needed for changes in industrial production lines. The key benefits of next-generation manufacturing systems are less downtimes and the production of small lot sizes down to lot size 1. I4.0 does not introduce a silver bullet technology, but requires a transformation of the system architecture of production systems. In the literature, however, there systematic guidance for designing manufacturing systems that address central I4.0 use cases like plug'n'produce and end-to-end communication is still missing, as are details on the infrastructure needed to enable I4.0 technologies such as Digital Twins. To contribute to filling this gap, this paper presents (i) a Digital Twin architecture blueprint driven by central I4.0 use cases and (ii) a prototypical open-source implementation of the architecture using the concept of the Asset Administration Shell.
  • Publication
    Enabling Industry 4.0 Service-Oriented Architecture through Digital Twins
    ( 2020)
    Schnicke, Frank
    ;
    Kuhn, Thomas
    ;
    Antonino, Pablo Oliveira
    A major goal of Industry 4.0 is to increase changeability of production processes, and to reduce the additional cost for individualized products. A service oriented production architecture can enable this goal. However, it demands changes in the software-based systems that compose the different levels of automation in a factory. Additionally, it requires a multitude of data to reflect the demands of service-oriented manufacturing processes. In this paper, we detail the minimal data to be contained in digital twins to enable an Industry 4.0 service-oriented architecture. We use two central Industry 4.0 use cases as drivers for deriving this data. We describe services by detailing their capabilities and their quality of service in terms of time, money and resulting product quality. Using these descriptions, we detail customer's order and the included product to be manufactured. Additionally, we describe challenges of the orchestration process like incompleteness of business processes and detail, how they can be solved using digital twins of the product, the service providers and the plant. Finally, we validate the proposed models by implementing the use cases on two model plants and give an experience report.
  • Publication
    Service-Based Architectures in Production Systems: Challenges, Solutions & Experiences
    ( 2020)
    Kuhn, Thomas
    ;
    Schnicke, Frank
    ;
    Antonino, Pablo Oliveira
    The automation industry is undergoing many changes. The fourth industrial revolution (Industrie 4.0) is the answer to changing markets and increasing quality requirements. Customers demand individualized products and smaller lot sizes. This requires the end-to-end digitalization of manufacturing processes and raises the need for system architectures for next-generation automation systems. Within the context of the national reference project BaSys 4, we researched a service-based architecture for the automation domain and integrated it with ongoing standardization activities. Service-oriented Architecture (SoA) is a proven architecture pattern from the domain of IT systems. It propagates reusable services that are orchestrated to create scalable applications. Our SoA is based on the concept of asset administration shells that realize digital twins, which are digital representations of production assets with unified interfaces that enable access to asset services and data. We explain and discuss realization concepts for digital twins, and illustrate our experiences with the transfer of the service-based architecture principle to the automation industry within the context of selected Industrie 4.0 use cases. We highlight solution approaches for the efficient realization of lot size 1 production as well as for creating digital twins of production assets, and discuss levels of Industrie 4.0 maturity.
  • Publication
    FERA: A Framework for Critical Assessment of Execution Monitoring Based Approaches for Finding Concurrency Bugs
    ( 2020)
    Jahic, Jasmin
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    Bauer, Thomas
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    Kuhn, Thomas
    ;
    Wehn, Norbert
    ;
    Antonino, Pablo Oliveira
    The software community has recognized the importance of concurrent multithreaded software and the criticality of concurrency bugs. However, it has still not fully acknowledged the complexity of the process for finding these bugs. When based on execution monitoring, the process includes tracing of the software execution, specification of concurrency bug models, modeling of synchronization mechanism patterns, and several other process steps and components. Existing approaches, however, focus only on the parts of the process for finding concurrency bugs (PFCB) and fail to notice their inter-dependencies, which affect the analysis outcome. Without a proper understanding of these inter-dependencies, the advances in this research area remain partially incremental and limited to specific use cases. In order to better understand this problem, we provide a model of a generic process for finding concurrency bugs (PFCB) and a framework for the critical assessment of execution-monitoring-based approaches for finding concurrency bugs (FERA). Our framework captures the inter-dependencies between the individual PFCB steps and establishes the relation between these inter-dependencies and the final outcome of the monitoring. The FERA framework is suitable for assessing the suitability of approaches for finding concurrency bugs, for specific software systems (e.g., with specific synchronization properties). With this paper, we demonstrate that finding concurrency bugs is not an isolated action consisting of applying an algorithm to an execution trace, but rather a continuous engineering process.
  • Publication
    A Simulator Coupling Architecture for the Creation of Digital Twins
    ( 2020)
    Kuhn, Thomas
    ;
    Antonino, Pablo Oliveira
    ;
    Bachorek, Adam
    Digital Twins are digital representations of real-world entities. Their behavior resembles the behavior of the real entity at all times. They are candidates for the evaluation of complex adaptive embedded systems, for example in the domains of autonomous driving, or industry 4.0 production systems. However, as most simulators are specialized and only simulate selected aspects of a system with highest accuracy, the creation of a Digital Twin requires the coupling of simulators and their simulation models. Related work indicates that this is still a labor-intensive and manual task. In this paper, we present an architecture framework that transfers approaches from Component-Based Software Engineering to simulator coupling. Simulators are encapsulated as simulation components with defined interfaces. The creation of a Digital Twin is supported by orchestrating simulation components. We present the formal definition of simulation components and our simulation framework, as well as the rules for coupling simulation components into Digital Twins.
  • Publication
    Blueprints for architecture drivers and architecture solutions for Industry 4.0 shopfloor applications
    ( 2019)
    Antonino, Pablo Oliveira
    ;
    Schnicke, Frank
    ;
    Zhang, Zai
    ;
    Kuhn, Thomas
    Industry 4.0 aims at evolving the current industrial processes towards directly connecting shopfloor machines to systems from different layers of the automation pyramid, such as Enterprise Resource Planning (ERP) or Manufacturing Execution Systems (MES). There are key functional and quality requirements that apply to most Industry 4.0 systems independent of the application domain, e.g., requirements related to interoperability, recoverability, security, and modifiability. Despite their importance, there is still a lack of understanding of (i) architecture drivers that focus on these quality aspects and (ii) architecture solutions for these architecture drivers that are adequate for a wide range of Industry 4.0 contexts. To contribute to filling this gap, we present in this paper (i) quality-centered architecture drivers derived from industrial cases, and (ii) architecture solutions based on the concepts of Digital Twins, Service-Oriented Architecture, and Virtual Automation Bus for four recurrent production plant scenarios. The architecture drivers and solutions presented in this paper were instantiated in different Industry 4.0 contexts, such as BaSys 4.0 (the German national reference project for Industry 4.0), and by the BaSys industry project partners.
  • Publication
    Towards Architecting Digital Twin-Pervaded Systems
    ( 2019)
    Bauer, Thomas
    ;
    Antonino, Pablo Oliveira
    ;
    Kuhn, Thomas
    Digital twins are virtual models for representing, monitoring, and controlling real-world products, entities, and processes, and are fundamental for enabling digitalization and continuous engineering processes. The usage of digital twins for engineering software-intensive systems will significantly change current business models, development approaches, and technologies. In this regard, the application scenarios and starting conditions for companies to introduce digital twins are manifold depending on their experience in software and system engineering, the maturity of their development processes, and the strategic management support and motivation. This article describes (i) challenges and impacts on the system development activities and architecture design approaches that are caused by the introduction and exploitation of digital twins, and also (ii) proposals for tailoring and extending traditional architecture-centric engineering processes to consider digital twin concepts.
  • Publication
    A constraint modeling framework for domain-specific languages
    ( 2019)
    Pschorn, Patrick
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    Antonino, Pablo Oliveira
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    Morgenstern, Andreas
    ;
    Kuhn, Thomas
    The growing usage of Domain Specific Modeling Languages (DSML) for architecture view frameworks induces a need for automatic verification of non-functional model properties like completeness and consistency. However, we argue that the high demand for tailored architecture view frameworks is not complemented by appropriate constraint specification facilities. OCL is a common language for defining modeling constraints, but industry user reports indicate that despite its accuracy, it is too complex to be adopted in industrial scale. Approaches that were proposed to simplify the use of OCL either operate on technical formalisms or lack tool support to express new, or more complex types of constraints that can be validated automatically on the model. To address this challenge, we present a constraint modeling framework for the specification and validation of constraints on DSMLs. A Constraint Modeling Language (CML) created based on this framework provides a high level constraint specification environment by using extensible template implementations to enable the automatic validation in computer aided software engineering (CASE) tools. We evaluate the approach in different industry projects and observe that using the proposed framework enhances understandability and effectiveness of constraint specification.
  • Publication
    Detection of conflicts and inconsistencies between architecture solutions
    ( 2019)
    Kallweit, Benno
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    Antonino, Pablo Oliveira
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    Jahic, Jasmin
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    Kuhn, Thomas
    ;
    Liggesmeyer, Peter
    This paper presents a semi-automated approach for detecting conflicts and inconsistencies between architecture solutions. Inconsistencies occur when two or more architecture solutions rely on each other but cannot be satisfied, and conflicts when there are contradictions within one single decision specification, such as contradictory variable range and value. The proposed approach comprises a set of checks followed by transformations of architecture solutions specified according to a domain-specific-language, also created in the context of this work, into state machines. The semi-automated approach is implemented as a plugin for the MagicDraw modeling tool, and was evaluated in a project from the automotive domain.