Adaptive Order Dispatching based on Reinforcement Learning: Application in a Complex Job Shop in the Semiconductor Industry

Heutige Produktionssysteme tendieren durch die Marktanforderungen getrieben zu immer kleineren Losgrößen, höherer Produktvielfalt und größerer Komplexität der Materialflusssysteme. Diese Entwicklungen stellen bestehende Produktionssteuerungsmethoden in Frage. Im Zuge der Digitalisierung bieten datenbasierte Algorithmen des maschinellen Lernens einen alternativen Ansatz zur Optimierung von Produktionsabläufen. Aktuelle Forschungsergebnisse zeigen eine hohe Leistungsfähigkeit von Verfahren des Reinforcement Learning (RL) in einem breiten Anwendungsspektrum. Im Bereich der Produktionssteuerung haben sich jedoch bisher nur wenige Autoren damit befasst. Eine umfassende Untersuchung verschiedener RL-Ansätze sowie eine Anwendung in der Praxis wurden noch nicht durchgeführt. Unter den Aufgaben der Produktionsplanung und -steuerung gewährleistet die Auftragssteuerung (order dispatching) eine hohe Leistungsfähigkeit und Flexibilität der Produktionsabläufe, um eine hohe Kapazitätsauslastung und kurze Durchlaufzeiten zu erreichen. Motiviert durch komplexe Werkstattfertigungssysteme, wie sie in der Halbleiterindustrie zu finden sind, schließt diese Arbeit die Forschungslücke und befasst sich mit der Anwendung von RL für eine adaptive Auftragssteuerung. Die Einbeziehung realer Systemdaten ermöglicht eine genauere Erfassung des Systemverhaltens als statische Heuristiken oder mathematische Optimierungsverfahren. Zusätzlich wird der manuelle Aufwand reduziert, indem auf die Inferenzfähigkeiten des RL zurückgegriffen wird. Die vorgestellte Methodik fokussiert die Modellierung und Implementierung von RL-Agenten als Dispatching-Entscheidungseinheit. Bekannte Herausforderungen der RL-Modellierung in Bezug auf Zustand, Aktion und Belohnungsfunktion werden untersucht. Die Modellierungsalternativen werden auf der Grundlage von zwei realen Produktionsszenarien eines Halbleiterherstellers analysiert. Die Ergebnisse zeigen, dass RL-Agenten adaptive Steuerungsstrategien erlernen können und bestehende regelbasierte Benchmarkheuristiken übertreffen. Die Erweiterung der Zustandsrepräsentation verbessert die Leistung deutlich, wenn ein Zusammenhang mit den Belohnungszielen besteht. Die Belohnung kann so gestaltet werden, dass sie die Optimierung mehrerer Zielgrößen ermöglicht. Schließlich erreichen spezifische RL-Agenten-Konfigurationen nicht nur eine hohe Leistung in einem Szenario, sondern weisen eine Robustheit bei sich ändernden Systemeigenschaften auf. Damit stellt die Forschungsarbeit einen wesentlichen Beitrag in Richtung selbstoptimierender und autonomer Produktionssysteme dar. Produktionsingenieure müssen das Potenzial datenbasierter, lernender Verfahren bewerten, um in Bezug auf Flexibilität wettbewerbsfähig zu bleiben und gleichzeitig den Aufwand für den Entwurf, den Betrieb und die Überwachung von Produktionssteuerungssystemen in einem vernünftigen Gleichgewicht zu halten

Working Notes from the 1992 AAAI Spring Symposium on Practical Approaches to Scheduling and Planning

The symposium presented issues involved in the development of scheduling systems that can deal with resource and time limitations. To qualify, a system must be implemented and tested to some degree on non-trivial problems (ideally, on real-world problems). However, a system need not be fully deployed to qualify. Systems that schedule actions in terms of metric time constraints typically represent and reason about an external numeric clock or calendar and can be contrasted with those systems that represent time purely symbolically. The following topics are discussed: integrating planning and scheduling; integrating symbolic goals and numerical utilities; managing uncertainty; incremental rescheduling; managing limited computation time; anytime scheduling and planning algorithms, systems; dependency analysis and schedule reuse; management of schedule and plan execution; and incorporation of discrete event techniques

Smart Sustainable Manufacturing Systems

With the advent of disruptive digital technologies, companies are facing unprecedented challenges and opportunities. Advanced manufacturing systems are of paramount importance in making key enabling technologies and new products more competitive, affordable, and accessible, as well as for fostering their economic and social impact. The manufacturing industry also serves as an innovator for sustainability since automation coupled with advanced manufacturing technologies have helped manufacturing practices transition into the circular economy. To that end, this Special Issue of the journal Applied Sciences, devoted to the broad field of Smart Sustainable Manufacturing Systems, explores recent research into the concepts, methods, tools, and applications for smart sustainable manufacturing, in order to advance and promote the development of modern and intelligent manufacturing systems. In light of the above, this Special Issue is a collection of the latest research on relevant topics and addresses the current challenging issues associated with the introduction of smart sustainable manufacturing systems. Various topics have been addressed in this Special Issue, which focuses on the design of sustainable production systems and factories; industrial big data analytics and cyberphysical systems; intelligent maintenance approaches and technologies for increased operating life of production systems; zero-defect manufacturing strategies, tools and methods towards online production management; and connected smart factories

Design and Management of Manufacturing Systems

Although the design and management of manufacturing systems have been explored in the literature for many years now, they still remain topical problems in the current scientific research. The changing market trends, globalization, the constant pressure to reduce production costs, and technical and technological progress make it necessary to search for new manufacturing methods and ways of organizing them, and to modify manufacturing system design paradigms. This book presents current research in different areas connected with the design and management of manufacturing systems and covers such subject areas as: methods supporting the design of manufacturing systems, methods of improving maintenance processes in companies, the design and improvement of manufacturing processes, the control of production processes in modern manufacturing systems production methods and techniques used in modern manufacturing systems and environmental aspects of production and their impact on the design and management of manufacturing systems. The wide range of research findings reported in this book confirms that the design of manufacturing systems is a complex problem and that the achievement of goals set for modern manufacturing systems requires interdisciplinary knowledge and the simultaneous design of the product, process and system, as well as the knowledge of modern manufacturing and organizational methods and techniques

Transnational production of Taiwanese integrated circuit industry in China

The trajectory of the Taiwanese economy over past decades has reflected transitions in global geo-economy towards a vertical specialisation of global trade, knowledge-based competition, variation of industrialisation in the Third World, regional trisection of the world economy, etc. Its industry, making remarkable progress based on a long-term national assistance, is involved in the outward direct investment whereby overseas production is arranged. Such strategic actions of industrial capital slice through national boundaries and, meanwhile, incorporate state-business relationships on a broader scale at a national level. The thesis seeks to portray the transnationalisation of the Taiwanese IC sector through its specific organisational processes and spatial dynamics with an aim to understanding the way that indigenous firms are associated with the home state and the convergence of IC production systems on subnational, transnational and global scales. This work finds that the outward expansion of the IC industrial capital reflects a spatial trend converging on China, the Yangtze River Delta in particular, owing to a reshuffle of the global electronic production chain. However, flow of capital and material along the chain across the Taiwan Strait move along a circuitous route. It also finds that a persistent inter-state feud accounts for the domestic debates over the westward investment of the IC capital. There is tension between the neo-liberalist logic of business practices and national intervention in a guided capitalist stance. It underlines the conflicts of imperative territoriality. On the one hand, the firms recognise the necessity of stretching industrial territories to the Mainland in consideration of sectoral competitiveness. On the other hand, what the state is concerned with lies not only in the impacts of industrial de-territorialisation upon domestic industries but also in the result of over-dependence upon China that would incorporate national economy into economic territories of the Great China Circle

Space station systems analysis study. Part 2, volume 3: Appendixes, Book 2: Supporting data (7 through 18)

Topics discussed include: (1) design considerations for a MARS sample return laboratory module for space station investigations; (2) crew productivity as a function of work shift arrangement; (3) preliminary analysis of the local logistics problem on the space construction base; (4) mission hardware construction operational flows and timelines; (5) orbit transfer vehicle concept definition; (6) summary of results and findings of space processing working review; (7) crew and habitability subsystem (option L); (8) habitability subsystem considerations for shuttle tended option L; (9) orbiter utilization in manned sortie missions; (10) considerations in definition of space construction base standard module configuration (option L); (11) guidance, control, and navigation subsystems; and (12) system and design tradeoffs

Using TRIZ methodology with lean production techniques applying SMED method in industrial environment

Dissertação de mestrado integrado em Engineering and Industrial ManagementDue to recognized benefits of Lean Production in the world, companies of all kinds and sizes are trying to implement the techniques to this production system. However, in their haste to reach short-term benefits of Lean Production, companies deploy sporadic and occasionally their tools without a clear link to global strategies. As a result, the majority fails in its attempt to be a Lean company and back to their old manufacturing systems. Nowadays it can also be applied the Theory of Inventive Problem Solving (TRIZ) by proposing a new approach to the Japanese Method of Lean Production. Traditionally, the effectiveness of new process is unpredictable as process relies largely on inspiration and the past experiences of the producing system. By integrating TRIZ problem-solving tools and its knowledge base, it’s proposed a new TRIZ-based approach to address this weakness in the processes. Through the case study, the combination of TRIZ methodology with Lean Production proposed model is verified. This demonstrates the helping relevance of TRIZ to the processes improving it. It is hoped that this case study will raise awareness among researchers so that more studies in this direction are conducted because TRIZ is a new approach methodology so it isn't yet too developed at this time. Using both methodologies (Lean and TRIZ) the goal wasn’t reached. It was supposed the changeover take less then 10 minutes and still more. Although it was a success using them together because the system improve. Using just SMED the system would improve “just” 56% but using SMED and TRIZ techniques the system was improved, using less 87% of the time taken in the beginning. As a result, it was found that Lean is best used when the tools are applied in combination with TRIZ Methodology. Combining these two methods the production become quicker and effective reducing the waste