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.Proth, J.M.Subject: search.filters.subject.group technology

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    Hierarchical Modeling Approach for Production Planning
    (1992) Harhalakis, George; Nagi, R.; Proth, J.M.; ISR
    Production management problems are complex owing to large dimensionality, wide variety of decisions of varying scope, focus and time-horizon, and disturbances. A hierarchical approach to these problems is a way to address this complexity, wherein the global problem is decomposed into a series of top-down sub- problems. We advocate that a single planning architecture cannot be employed for all planning problems. We propose a multi-layer hierarchical decomposition which is dependent on the complexity of the problem, and identify the factors influencing complexity. A systematic stepwise design approach for the construction of the hierarchy and inputs required are presented. The subsequent operation of the hierarchy in an unreliable environment is also explained. Aggregation schemes for model reduction have been developed and blended with a time-scale decomposition of activities to provide the theoretical foundation of the architecture. It is also hoped that this methodology can be applied to other such large-scale complex decision making problems.
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    Class: Computerized LAyout Solutions Using Simulated Annealing
    (1990) Minis, Ioannis; Harhalakis, George; Jajodia, Satish K.; Proth, J.M.; ISR
    A new method (Computerized LAyout Solutions using Simulated annealing - CLASS) that considers the inter-cell and intra-cell layout problems in a cellular manufacturing environment is presented. It addresses the relative placement of equidimensional manufacturing entities within a discrete solution space in an attempt to minimize the total material flow (cost) between these entities. An approach to accommodate the relative sizes of the entities is also presented. The method is based on Simulated Annealing, which has been successfully applied for the solution of combinatorial problems. A major advantage of this technique is the insensitivity of the final solution to the initial conditions. In addition, some important practical issues such as intra-cell layout of machines in pre-determined configurations (e.g. row-wise or circular arrangements), have been addressed. Several comparisons were made with some of the existing approaches for facility layout, such as CRAFT, HC63-66, etc. that yielded results of equal or better quality for each of eight classical test problems.
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    Manufacturing Cell Design Using Simulated Annealing: an Industrial Application
    (1990) Harhalakis, George; Proth, J.M.; Xie, X.L.; ISR
    In this paper, we give a brief summary of simulated annealing procedures used to solve combinatorial optimization problems. We then present the manufacturing cell design problem which consists of designing cells of limited size in order to minimize inter- cell traffic. We show how to use a SA approach to obtain a good, if not optimum, solution to this problem. Finally, we apply this approach to an industrial problem and compare the results to the ones obtained using the so-called twofold heuristic algorithm.