Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

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Author: search.filters.author.Herrmann, Jeffrey W.Subject: search.filters.subject.computer integrated manufacturing CIM

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Now showing 1 - 7 of 7
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    Sequencing Wafer Handler Moves to Improve the Performance of Hybrid Cluster Tools
    (2000) Nguyen, Manh-Quan T.; Herrmann, Jeffrey W.; ISR
    Cluster tools are highly integrated machines that can perform a sequence of semiconductor manufacturing processes. The sequence of wafer handler moves affects the total time needed to process a set of wafers.

    Reducing this time can reduce cycle time, reduce tool utilization, and increase tool capacity. This paper introduces the cluster tool scheduling problem for hybrid cluster tools, which are multiple-stage tools that have at least one stage with two or more parallel chambers.

    This paper presents algorithms that can find superior sequences of wafer handler moves. Experimental results show that the tool performance can be improved significantly if the wafer handler follows a cyclic sequence instead of using a dispatching rule.

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    Sequencing Wafer Handler Moves to Improve the Performance of Sequential Cluster Tools
    (2000) Herrmann, Jeffrey W.; Nguyen, Manh-Quan T.; ISR
    Cluster tools are highly integrated machines that can perform a sequence of semiconductor manufacturing processes. The sequence of wafer handler moves affects the total time needed to process a set of wafers. Reducing this time can reduce cycle time, reduce tool utilization, and increase tool capacity. This paper introduces the cluster tool scheduling problem for sequential cluster tools and describes a branch-and-bound algorithm that can find an optimal sequence of wafer handler moves. In addition, we enumerate the set of 1-unit cyclic sequences for two- and three-stage sequential cluster tools. Experimental results show that the tool performance can be improved significantly if the wafer handler follows a cyclic sequence instead of using a dispatching rule.
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    Reducing Manufacturing Cycle Time during Product Design
    (1999) Herrmann, Jeffrey W.; Chincholkar, Mandar; ISR
    This paper describes an approach that can reduce manufacturing cycle time during product design. Design for production (DFP) determines how manufacturing a new product design affects the performance of the manufacturing system. This includes design guidelines, capacity analysis, and estimating manufacturing cycle times. Performing these tasks early in the product development process can reduce product development time. Previous researchers have developed various DFP methods for different problem settings. This paper discusses the relevant literature and classifies these methods. The paper presents a systematic DFP approach and a manufacturing system model that can be used to estimate the manufacturing cycle time of a new product. This approach gives feedback that can be used to eliminate cycle time problems. This paper focuses on products that are produced in one facility. We present an example that illustrates the approach and discuss a more general approach for other multiple-facility settings.
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    Using Neural Networks to Generate Design Similarity Measures
    (1999) Balasubramanian, Sundar; Herrmann, Jeffrey W.; Herrmann, Jeffrey W.; ISR
    This paper describes a neural network-based design similarity measure for a variant fixture planning approach. The goal is to retrieve, for a new product design, a useful fixture from a given set of existing designs and their fixtures. However, since calculating each fixture feasibility and then determining the necessary modifications for infeasible fixtures would require too much effort, the approach searches quickly for the most promising fixtures. The proposed approach uses a design similarity measure to find existing designs that are likely to have useful fixtures. The use of neural networks to generate design similarity measures is explored.This paper describes the back-propagation algorithm for network learning and highlights some of the implementation details involved. The neural network-based design similarity measure is compared against other measures that are based on a single design attribute.
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    Evaluating Sheet Metal Nesting Decisions
    (1998) Herrmann, Jeffrey W.; Delalio, David R.; ISR
    This paper describes models that estimate the cost and time of sheet metal punching when nesting (batching) orders. These models help decision-makers plan production and evaluate the impact of changing the nesting policy. In addition, we use them to formulate a nesting optimization problem. Finally, we use the models to evaluate the sensitivity of the nesting policy to manufacturing parameters. We conclude that dynamic nesting can reduce the capacity requirements, material requirements, and cost of sheet metal punching.
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    An Internet-Based Work Instructions System
    (1998) Herrmann, Jeffrey W.; Lin, Edward; Minis, Ioannis; ISR
    The Black & Decker factory in Easton, Maryland, uses parallel, off-line assembly lines to produce multiple models in small, infrequent production runs. The University of Maryland and Black & Decker have implemented an Internet-based work instructions system that supports parallel, off-line assembly. Black & Decker personnel create and update easy-to-read paperless work instructions, and each assembly station automatically retrieves the correct paperless work instructions and displays them.
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    Design Similarity Measures for Process Planning and Design Evaluation
    (1997) Herrmann, Jeffrey W.; Singh, Gurdip; ISR
    Design engineers and process planners need to search for similar designs. Design engineers use similar designs to estimate a new design's manufacturability. Like process planners, who need to generate process plans before production begins, design engineers can use an existing, similar design's plan to create a new process plan. Then, they can evaluate the new design. Variant process planning, a common process planning approach, uses a design similarity measure to identify the most similar design and retrieve a useful process plan. However, standard design similarity measures do not explicitly consider the production process. This paper presents an approach for developing a new class of plan-based design similarity measures. Such a measure explicitly exploits process plan similarity and thus improves the variant process planning approach. An example illustrates the approach and compares the new measure and a traditional group technology code-based approach.