Intelligent production control for time-constrained complex job shops

Im Zuge der zunehmenden Komplexität der Produktion wird der Wunsch nach einer intelligenten Steuerung der Abläufe in der Fertigung immer größer. Sogenannte Complex Job Shops bezeichnen dabei die komplexesten Produktionsumgebungen, die deshalb ein hohes Maß an Agilität in der Steuerung erfordern. Unter diesen Umgebungen sticht die besonders Halbleiterfertigung hervor, da sie alle Komplexitäten eines Complex Job-Shop vereint. Deshalb ist die operative Exzellenz der Schlüssel zum Erfolg in der Halbleiterindustrie. Diese Exzellenz hängt ganz entscheidend von einer intelligenten Produktionssteuerung ab. Ein Hauptproblem bei der Steuerung solcher Complex Job-Shops, in diesem Fall der Halbleiterfertigung, ist das Vorhandensein von Zeitbeschränkungen (sog. time-constraints), die die Transitionszeit von Produkten zwischen zwei, meist aufeinanderfolgenden, Prozessen begrenzen. Die Einhaltung dieser produktspezifischen Zeitvorgaben ist von größter Bedeutung, da Verstöße zum Verlust des betreffenden Produkts führen. Der Stand der Technik bei der Produktionssteuerung dieser Dispositionsentscheidungen, die auf die Einhaltung der Zeitvorgaben abzielen, basiert auf einer fehleranfälligen und für die Mitarbeiter belastenden manuellen Steuerung. In dieser Arbeit wird daher ein neuartiger, echtzeitdatenbasierter Ansatz zur intelligenten Steuerung der Produktionssteuerung für time-constrained Complex Job Shops vorgestellt. Unter Verwendung einer jederzeit aktuellen Replikation des realen Systems werden sowohl je ein uni-, multivariates Zeitreihenmodell als auch ein digitaler Zwilling genutzt, um Vorhersagen über die Verletzung dieser time-constraints zu erhalten. In einem zweiten Schritt wird auf der Grundlage der Erwartung von Zeitüberschreitungen die Produktionssteuerung abgeleitet und mit Echtzeitdaten anhand eines realen Halbleiterwerks implementiert. Der daraus resultierende Ansatz wird gemeinsam mit dem Stand der Technik validiert und zeigt signifikante Verbesserungen, da viele Verletzungen von time-constraints verhindert werden können. Zukünftig soll die intelligente Produktionssteuerung daher in weiteren Complex Job Shop-Umgebungen evaluiert und ausgerollt werden

Micro/Nano Structures and Systems

Micro/Nano Structures and Systems: Analysis, Design, Manufacturing, and Reliability is a comprehensive guide that explores the various aspects of micro- and nanostructures and systems. From analysis and design to manufacturing and reliability, this reprint provides a thorough understanding of the latest methods and techniques used in the field. With an emphasis on modern computational and analytical methods and their integration with experimental techniques, this reprint is an invaluable resource for researchers and engineers working in the field of micro- and nanosystems, including micromachines, additive manufacturing at the microscale, micro/nano-electromechanical systems, and more. Written by leading experts in the field, this reprint offers a complete understanding of the physical and mechanical behavior of micro- and nanostructures, making it an essential reference for professionals in this field

A Comprehensive Guide to Solar Energy Systems With Special Focus on Photovoltaic Systems

This book, the most advanced and research focused text on all aspects of solar energy engineering, is a must have edition on the present state of solar technology, integration and worldwide distribution. In addition, the book provides a high-level assessment of the growth trends in photovoltaics and how investment, planning and economic infrastructure can support those innovations. Each chapter includes a research overview with a detailed analysis and new case studies that look at how recent research developments can be applied. Written by some of the most forward-thinking professionals, this book is an invaluable reference for engineers. Key Features Contains analysis of the latest high-level research and explores real world application potential in relation to developments Uses system international (SI) units and imperial units throughout to appeal to global engineers Offers measurable data written by a world expert in the field on the latest developments in this fast moving and vital subject Readership Energy engineers, researchers, graduate students, professors and lecturers in Engineering, scientists and engineers working in energy, industrialists and engineers working in future energy development

The 1991 3rd NASA Symposium on VLSI Design

Papers from the symposium are presented from the following sessions: (1) featured presentations 1; (2) very large scale integration (VLSI) circuit design; (3) VLSI architecture 1; (4) featured presentations 2; (5) neural networks; (6) VLSI architectures 2; (7) featured presentations 3; (8) verification 1; (9) analog design; (10) verification 2; (11) design innovations 1; (12) asynchronous design; and (13) design innovations 2

New high volume production, production linkages and regional development: the case of the microcomputer hardware industry in Ireland and Scotland

The dissertation explores the regional development effects, via production linkages, of subsidiaries of multinational enterprises that have adopted New High Volume Production (NHVP) approaches, in non-core regions NHVP approaches are positioned amid other post-Fordist forms of industrial organisation. There are literatures that suggest that the adoption of NHVP approaches will have positive implications for regional development of non-core regions because of greater indirect, backward linkage, effects. Theoretically, local linkage formation or buyersuppher proximity in NHVP industries might be the outcome of three drivers. It can be driven by a search for efficiency in product flow/logistics, efficiency in formal information exchange in the context of inter-firm functional integration and by sociocultural and institutional factors enhancing information flow in a local milieu. This dissertation investigates the role of the first two drivers in shaping the geographical configuration of backward linkages in NHVP industries. This is done in a case study of the microcomputer hardware industry in Ireland and Scotland. The findings of the case study do not support the positive suggestions of greater backward linkage effects. A detailed examination of the supply chains of the subsidiaries of foreign microcomputer assemblers shows that the vast majority of components and parts were imported from the Far East and, to a lesser extent, the USA. It is shown that efficiency in technical information exchange was a relatively insignificant driver for buyer-supplier proximity, and how this fact was related to the particular way NHVP manifested itself m the microcomputer hardware industry. Similarly, in relation to most material inputs, logistical efficiency did not lead to buyer-suppher proximity. It is shown that the supply chains generally involved inbound inventories, stored in local warehouses - ‘hubs’ - from where the manufacturing lines were supplied on a very frequent basis. This logistical solution should, however, not be interpreted as sub-optimal. A detailed examination of the key logistics data shows that the inbound logistics pipelines were tightly managed and that inventory levels and shipment frequencies were consistent with modem comprehensive logistics management principles. The dissertation also explores the actual impact that the NHVP plants had on the quality and competitiveness of their local suppliers in non-core regions. The findings show that, although the subsidiaries of the foreign microcomputer assemblers created few local linkages, they had a significant positive impact on the quality and competitiveness of nearly all local suppliers they were dealing with

Management: A continuing literature survey with indexes, March 1975

A special bibliography listing 1,064 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in 1974 is presented