29 research outputs found
Production Scheduling
Generally speaking, scheduling is the procedure of mapping a set of tasks or jobs (studied objects) to a set of target resources efficiently. More specifically, as a part of a larger planning and scheduling process, production scheduling is essential for the proper functioning of a manufacturing enterprise. This book presents ten chapters divided into five sections. Section 1 discusses rescheduling strategies, policies, and methods for production scheduling. Section 2 presents two chapters about flow shop scheduling. Section 3 describes heuristic and metaheuristic methods for treating the scheduling problem in an efficient manner. In addition, two test cases are presented in Section 4. The first uses simulation, while the second shows a real implementation of a production scheduling system. Finally, Section 5 presents some modeling strategies for building production scheduling systems. This book will be of interest to those working in the decision-making branches of production, in various operational research areas, as well as computational methods design. People from a diverse background ranging from academia and research to those working in industry, can take advantage of this volume
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
Intelligent shop scheduling for semiconductor manufacturing
Semiconductor market sales have expanded massively to more than 200 billion dollars annually accompanied by increased pressure on the manufacturers to provide higher quality products at lower cost to remain competitive. Scheduling of semiconductor manufacturing is one of the keys to increasing productivity, however the complexity of manufacturing high capacity semiconductor devices and the cost considerations mean that it is impossible to experiment within the facility. There is an immense need for effective decision support models, characterizing and analyzing the manufacturing process, allowing the effect of changes in the production environment to be predicted in order to increase utilization and enhance system performance. Although many simulation models have been developed within semiconductor manufacturing very little research on the simulation of the photolithography process has been reported even though semiconductor manufacturers have recognized that the scheduling of photolithography is one of the most important and challenging tasks due to complex nature of the process.
Traditional scheduling techniques and existing approaches show some benefits for solving small and medium sized, straightforward scheduling problems. However, they have had limited success in solving complex scheduling problems with stochastic elements in an economic timeframe. This thesis presents a new methodology combining advanced solution approaches such as simulation, artificial intelligence, system modeling and Taguchi methods, to schedule a photolithography toolset. A new structured approach was developed to effectively support building the simulation models. A single tool and complete toolset model were developed using this approach and shown to have less than 4% deviation from actual production values. The use of an intelligent scheduling agent for the toolset model shows an average of 15% improvement in simulated throughput time and is currently in use for scheduling the photolithography toolset in a manufacturing plant
A framework for generating operational characteristic curves for semiconductor manufacturing systems using flexible and reusable discrete event simulations
This thesis proposes a framework for generating operating curves for semiconductor manufacturing facilities using a modular flexible discrete event simulation (DES) model embedded in an application that automates the design of experiments for the simulations. Typically, operating curves are generated using analytical queueing models that are difficult to implement and hence, can only be used for benchmarking purposes. Alternatively, DES models are more capable of capturing the complexities of a semiconductor manufacturing facility such as re-entrancy, rework and non-identical toolsets. However, traditional craft-based simulations require much time and resources. The proposed methodology aims to reduce this time by automatically calculating the parameters for experimentation and generating the simulation model. It proposes a novel method to more appropriately allocate simulation effort by selecting design points more relevant to the operating curve.
The methodology was initially applied to a single toolset model and tested as a pilot case study using actual factory data. Overall, the resulting operating curves matched that of the actual data. Subsequently, the methodology was applied to a full semiconductor manufacturing facility, using datasets from the Semiconductor Wafer Manufacturing Data Format Specification. The automated framework was shown to generate the curves rapidly and comparisons against a number of queueing model equivalents showed that the DES curves were more accurate. The implications of this work mean that on deployment of the application, semiconductor manufacturers can quickly obtain an accurate operating curve of their factory that could be used to aid in capacity planning and enable better decision-making regarding allocation of resources
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
Design and control of a 6-Degree-of-Freedom levitated positioner with high precision
This dissertation presents a high-precision positioner with a novel superimposed
concentrated-field permanent-magnet matrix. This extended-range multi-axis positioner can
generate all 6-DOF (degree-of-freedom) motions with only a single moving part. It is actuated
by three planar levitation motors, which are attached on the bottom of the moving part. Three
aerostatic bearings are used to provide the suspension force against the gravity for the system.
The dynamic model of the system is developed and analyzed. And several control techniques
including SISO (single input and single output) and MIMO (multi inputs and multi outputs)
controls are discussed in the dissertation. The positioner demonstrates a position resolution of 20
nm and position noise of 10 nm rms in x and y and 15 nm rms in z. The angular resolution
around the x-, y-, and z-axes is in sub-microradian order. The planar travel range is 160 mm ??
160 mm, and the maximum velocity achieved is 0.5 m/s at a 5-m/s2 acceleration, which can
enhance the throughput in precision manufacturing. Various experimental results are presented in
this dissertation to demonstrate the positioner??s capability of accurately tracking any planar
trajectories. Those experimental results verified the potential utility of this 6-DOF high-precision
positioner in precision manufacturing and factory automation
Greening Global Value Chains: A Conceptual Framework for Policy Action
This is Chapter 6 of the Global Value Chain Development Report 2023. The Global Value Chain (GVC) Development Report 2023 explores approaches to build resilient and sustainable GVCs. It provides an overview of the most recent trends in GVCs, assesses the effects of recent trade tensions and the COVID-19 pandemic on GVCs, and illustrates changes in the nature of supply chains. It also analyses the challenges of climate change to GVCs and proposes policy options for enhancing inclusive development through GVC participation
Proceedings of the 2nd Conference on Production Systems and Logistics (CPSL 2021)
Proceedings of the CPSL 202