Now showing 1 - 10 of 10
  • Publication
    Cyber-physical systems in manufacturing
    ( 2016)
    Monostori, László
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    Kádár, Botond
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    Kondoh, Shinsuke
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    Kumara, Soundar R.
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    Reinhart, Gunther
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    Schuh, Günther
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    Sihn, Wilfried
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    Ueda, Kanji
    One of the most significant advances in the development of computer science, information and communication technologies is represented by the cyber-physical systems (CPS). They are systems of collaborating computational entities which are in intensive connection with the surrounding physical world and its on-going processes, providing and using, at the same time, data-accessing and data-processing services available on the Internet. Cyber-physical production systems (CPPS), relying on the latest, and the foreseeable further developments of computer science, information and communication technologies on one hand, and of manufacturing science and technology, on the other, may lead to the 4th industrial revolution, frequently noted as Industrie 4.0. The paper underlines that there are significant roots in general - and in particular to the CIRP community - which point towards CPPS. Expectations towards research in and implementation of CPS and CPPS are outlined and some case studies are introduced. Related new R&D challenges are highlighted.
  • Publication
    Complementary research and education opportunities - a comparison of learning factory facilities and methodologies at TU Wien and MTA SZTAKI
    ( 2016)
    Kemeny, Zsolt
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    Nacsa, János
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    Erdos, Gábor
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    Glawar, Robert
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    Sihn, Wilfried
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    Monostori, László
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    Ilie-Zudor, Elisabeth
    Typical learning factories are characterized by selective simplification or scaling-down of complex and large-scale production processes, while also safely containing risks in the case of process failures inherent to experimental and didactic activities. The variety of aspects preserved by these scaled-down environments allow different approaches to be taken in research and education. The paper compares two facilities, at TU Wien and at MTA SZTAKI in Budapest, respectively, and highlights differences in their modes of operation, the resulting variations of course-based vs. project-based didactic approaches, as well as their place in technical higher education.
  • Publication
    A holistic approach for quality oriented maintenance planning supported by data mining methods
    ( 2016)
    Glawar, Robert
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    Kemeny, Zsolt
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    Nemeth, Tanja
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    Matyas, Kurt
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    Monostori, László
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    Sihn, Wilfried
    Appropriate maintenance measures, which are carried out at the right time are a key factor to secure plant availability, product quality and process efficiency in modern manufacturing systems. Established maintenance strategies oftentimes lack in combining these strongly related aspects. They are not capable to anticipate in a holistic way and therefore lead to unnecessarily high maintenance efforts, wasted resources and the occurrence of quality and availability impairments. In order to realize a holistic and anticipatory approach for maintenance planning, a methodology which consistently compiles and correlates various data via ""cause and effect"" coherences is depicted. By breaking down the production facilities on component level a basis is set to link condition monitoring data, wear data, quality and production data by using data mining methods. This framework enables the identification of maintenance-critical conditions and the prediction of failure moments and quality deviations.
  • Publication
    An inverse economic lot-sizing approach to eliciting supplier cost parameters
    ( 2014)
    Egri, Péter
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    Kis, Tamás
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    Kovács, András
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    Váncza, József
    Recent literature on supply chain coordination offers a wide range of game theoretic and optimization approaches that ensure efficient planning in the supply chain, but assume that the involved parties have complete information about each other. However, in reality, complete information is rarely available, and those models alone do not present any incentive for the parties to reveal their private information, e.g., the cost parameters that they use when solving their planning problems. This paper proposes an inverse lot-sizing model for eliciting the cost parameters of a supplier from historic demand vs. optimal delivery lot-size pairs, gathered during repeated earlier encounters. It is assumed that the supplier solves a single-item, multi-period, uncapacitated lot-sizing problem with backlogs to optimality to calculate its lot-sizes, and the buyer is aware of this fact. The inverse lot-sizing problem is reformulated to an inverse shortest path problem, which is, in tu rn, solved as a linear program. This model is used to compute the ratios of the supplier's cost parameters, i.e., the setup, the holding, and the backlog cost parameters consistent with all the historic samples. The elicited cost parameters can be used as input for various game theoretic or bilevel optimization models for supply chain coordination. Computational experiments on randomly generated problem instances indicate that the approach is very efficient in predicting future supplier actions from the historic records.
  • Publication
    Capacity management for assembly systems with dedicated and reconfigurable resources
    ( 2014)
    Gyulai, Dávid
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    Kádár, Botond
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    Kovács, András
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    Monostori, László
    Managing changes and disturbances resulted by fluctuating order streams and diverse product portfolios requires efficient capacity management decisions and production planning strategies. High volume products can be produced cost efficiently on dedicated assembly lines, while the assembly of low runners is more efficient on reconfigurable lines. In the paper a hierarchical planning decision workflow is introduced to assign the products to dedicated and reconfigurable lines, and to optimize the system configuration and the production plan of the reconfigurable system in an integrated way. The proposed solution is demonstrated through the results of an industrial case study.
  • Publication
    Complexity in engineering design and manufacturing
    ( 2012)
    ElMaraghy, Waguih
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    ElMaraghy, Hoda A.
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    Tomiyama, Tetsuo
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    Monostori, László
    This paper reviews the breadth of complexity of the design process, products, manufacturing, and business. Manufacturing is facing unprecedented challenges due to increased variety, market volatility and distributed global manufacturing. A fundamental residue of globalization and market uncertainty is the increasing complexity of manufacturing, technological and economic systems. The nature and sources of complexity in these areas are reviewed and complexity modeling and management approaches are discussed. Enterprises that can mitigate the negative aspects of complexity while managing its positives should thrive on the continuous change and increasing complexity. To reap these benefits in the future, manufacturing companies need to not only adopt flexible technical solutions but must also effectively innovate and manage complex socio-technical systems.
  • Publication
    Design and assessment of quality control loops for stable business processes
    ( 2012)
    Schmitt, Robert
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    Monostori, László
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    Glöckner, Henrik
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    Viharos, Zsolt János
    Due to their open and dynamic character, business processes in lack of adequate feedback mechanisms tend to become unstable in case of unanticipated disturbances or target adjustments. In order to face this challenge and to ensure entrepreneurial quality the implementation of quality control loops is proposed, whose design is derived from cybernetics. The paper discusses requirements for the characteristics of quality control loops and presents a new approach for their assessment implemented in software. The developed tool also serves as a knowledge exchange platform since it provides an opportunity for exchanging standardized control loop elements.
  • Publication
    A system for the detailed scheduling of wind farm maintenance
    ( 2011)
    Kovács, András
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    Erdös, Gábor
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    Viharos, Zsolt János
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    Monostori, László
    As the share of wind energy increases on the global energy market, the efficient operation of wind farms gains an ever growing significance. Among operational decisions, the planning and scheduling of maintenance operations are crucial for the availability of turbines, as well as for the operational costs. The paper introduces a system that performs the detailed scheduling of maintenance operations at a set of wind farms maintained by common personnel. The scheduling problem is modeled and solved as a mixed-integer linear program. The system constitutes a module of an integrated framework for condition monitoring, diagnosis, and maintenance of wind turbines.
  • Publication
    Cooperative and responsive manufacturing enterprises
    ( 2011)
    Váncza, József
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    Monostori, László
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    Lutters, D.
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    Kumara, S.R.
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    Tseng, M.
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    Valckenaers, P.
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    Brussel, H. van
    The paper discusses manufacturing enterprises' compelling challenges that are directly stemming from generic conflicts between competition and cooperation, local autonomy and global behavior, design and emergence, planning and reactivity, uncertainty and a plethora of information. Responses in product and service design, organization of production networks, planning and management of operations, as well as production control are surveyed. As illustrated through industrial case studies, production engineering should integrate a rich body of interdisciplinary results together with contemporary information and communication technologies in order to facilitate cooperation and responsiveness that are vital in competitive, sustainable manufacturing.
  • Publication
    Robust production control against propagation of disruptions
    ( 2011)
    Tolio, Tullio
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    Urgo, Marcello
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    Váncza, József
    In hierarchical production control systems, planning decides on capacities and operations so as to meet demand, while scheduling should guarantee the execution of production plans even in face of uncertainties. The management practice advocates rolling horizon approaches despite the danger of plan nervousness. We propose a novel framework to handle uncertainties closer to the root of their sources, when scheduling local resources. The method keeps the complexity of planning and scheduling at bay and stops the propagation of local disruptions to other resources. The paper presents the theoretical model, the solution technique, and shows their applicability on a case study taken from the tool industry.