369 research outputs found

    Simulation for Product Driven Systems

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    Due to globalisation, companies have to become more and more agile in order to face demand fluctuations and growing customisation needs. Indeed, the mass production market moves to a mass customization one, which could be defined as the production of a wide variety of end products at a low unit cost. During last years, many efforts have been done in order to improve operating system reactivity (with the Flexible Manufacturing initiative for example), but the manufacturing decision process did not really change, and then doesn't enable to fully make the most of these new operating system skills. Facing these new trends, a lot of new research works are focusing on identification technologies, like Auto-ID, biometry or vision ones. Radio Frequency Identification technology (RFID) represents a quick and safe way to track products, opening the way of linking informational and physical flows, and providing an accurate, real time vision of the shop floor. These new technologies appear like a catalyst to change the fifty years old way of controlling production through traditional MRP² systems

    A novel throughput control algorithm for semi-heterarchical industry 4.0 architecture

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    Modern market scenarios are imposing a radical change in the production concept, driving companies’ attention to customer satisfaction through increased product customization and quick response strategies to maintain competitiveness. At the same time, the growing development of Industry 4.0 technologies made possible the creation of new manufacturing paradigms in which an increased level of autonomy is one of the key concepts to consider. Taking the advantage from the recent development around the semi-heterarchical architecture, this work proposes a first model for the throughput control of a production system managed by such an architecture. A cascade control algorithm is proposed considering work-in-progress (WIP) as the primary control lever for achieving a specific throughput target. It is composed of an optimal control law based on an analytical model of the considered production system, and of a secondary proportional-integral-derivative controller capable of performing an additional control action that addresses the error raised by the theoretical model’s. The proposed throughput control algorithm has been tested in different simulated scenarios, and the results showed that the combination of the control actions made it possible to have continuous adjustment of the WIP of the controlled production system, maintaining it at the minimum value required to achieve the requested throughput with nearly zero errors

    Multi Agent Systems in Logistics: A Literature and State-of-the-art Review

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    Based on a literature survey, we aim to answer our main question: “How should we plan and execute logistics in supply chains that aim to meet today’s requirements, and how can we support such planning and execution using IT?†Today’s requirements in supply chains include inter-organizational collaboration and more responsive and tailored supply to meet specific demand. Enterprise systems fall short in meeting these requirements The focus of planning and execution systems should move towards an inter-enterprise and event-driven mode. Inter-organizational systems may support planning going from supporting information exchange and henceforth enable synchronized planning within the organizations towards the capability to do network planning based on available information throughout the network. We provide a framework for planning systems, constituting a rich landscape of possible configurations, where the centralized and fully decentralized approaches are two extremes. We define and discuss agent based systems and in particular multi agent systems (MAS). We emphasize the issue of the role of MAS coordination architectures, and then explain that transportation is, next to production, an important domain in which MAS can and actually are applied. However, implementation is not widespread and some implementation issues are explored. In this manner, we conclude that planning problems in transportation have characteristics that comply with the specific capabilities of agent systems. In particular, these systems are capable to deal with inter-organizational and event-driven planning settings, hence meeting today’s requirements in supply chain planning and execution.supply chain;MAS;multi agent systems

    Agent-based transportation planning compared with scheduling heuristics

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    Here we consider the problem of dynamically assigning vehicles to transportation orders that have di¤erent time windows and should be handled in real time. We introduce a new agent-based system for the planning and scheduling of these transportation networks. Intelligent vehicle agents schedule their own routes. They interact with job agents, who strive for minimum transportation costs, using a Vickrey auction for each incoming order. We use simulation to compare the on-time delivery percentage and the vehicle utilization of an agent-based planning system to a traditional system based on OR heuristics (look-ahead rules, serial scheduling). Numerical experiments show that a properly designed multi-agent system may perform as good as or even better than traditional methods

    A new approach for the validation of conceptual holonic constructions

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    The concepts of holon and holarchy were first applied in the manufacturing world to develop Holonic Manufacturing Systems. Since then, they have been used in many fields and have proved to be applicable concepts for developing applications in any business area. Resulting applications are based on conceptual holonic constructions. Like any model, a holarchy needs to be validated under real circumstances. Such validation assures the quality of the holarchy before it is implemented. In general, validation research tends to target: 1) the specific types of holons handled in each proposal and/or the selected development paradigms; and 2) algorithm performance rather than architecture quality. This paper proposes and evaluates a methodology that focuses on the quality of the architecture. This methodology is able to validate any holonic architecture built to meet trade requirements. Moreover, this is a general-purpose methodology. Therefore, the methodology would be valid for any domain and would not be invalidated by holon types and/or implementation paradigms emerging, changing or falling into disuse. For this purpose, we consider holonic architectures as conceptual models, using the pure holon and holarchy concepts and passing up not only any specific implementation paradigm but also any set of specific holon types

    Using online simulation in Holonic Manufacturing Systems

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    Journal homepage: www.elsevier.com/locate/engappaiInternational audienceThis paper deals with the use of online simulation on Holonic Manufacturing Systems. Concepts needed for the use of online simulation in a classical hierarchical system were already defined, the observer being the central one. The behavior's differences between both classes of systems are studied to determine the best way to adapt these concepts to this new environment. In the PROSA reference architecture, staff holons were chosen to welcome the simulation models and the observer. An application on an industrial sized Holonic Manufacturing System is described to demonstrate the validity of the approach

    Proceedings of the third International Workshop of the IFIP WG5.7

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    Contents of the papers presented at the international workshop deal with the wide variety of new and computer-based techniques for production planning and control that has become available to the scientific and industrial world in the past few years: formal modeling techniques, artificial neural networks, autonomous agent theory, genetic algorithms, chaos theory, fuzzy logic, simulated annealing, tabu search, simulation and so on. The approach, while being scientifically rigorous, is focused on the applicability to industrial environment
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