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.Harhalakis, GeorgeSubject: search.filters.subject.automation

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    A Step-Wise Specification of a Manufacturing System Using Petri Nets
    (1992) Claver, J.F.; Harhalakis, George; Proth, J.M.; Savi, V.M.; Xie, X.L.; ISR
    Our experience, mainly based on two recently conducted real-life studies for some European companies, reveals that a natural way to proceed with the modeling and specification of large manufacturing system is to decompose the model of the entire system into sub-systems (referred to as modules). Models for modules are developed, and then integrated to model the entire system. Several problems arise in this process. If we express these problems from the users' point of view, they can be summarized by the following two issues: (i) how to decompose the whole system into sub-systems modules in order to have tractable (thus small) models exposing "good" properties? (ii) how then to integrate the module models in order to reach a global model also exposing "good" properties?
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    Some Open Problems in the Design and Use of Modern Production Systems
    (1992) Harhalakis, George; Proth, J.M.; ISR
    During the past two decades, manufacturing systems have moved towards automation, integration and modularity. These trends will certainly continue in the future due to the constraints of the market and to evolution of the resources and worker requirements. As a consequence, design and use of manufacturing systems are increasingly expensive. Numerous methods and tools have been developed to face up to this situation, but some complementary aids could be provided for designers and manufacturing engineers. The goal of this paper is to present important open problems whose solutions could certainly improve significantly the design and use of the modern production system.
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    INformation Systems for Integrated Manufacturing (INSIM) - A Design Methodology
    (1991) Harhalakis, George; Lin, Chang-Pin; Mark, Leo; Muro, P.R.; ISR
    Full control and management of information flow in manufacturing has not yet been achieved, mainly because of the data inconsistencies and lack of established functional relationships among different manufacturing application systems. Research toward CIM has been concentrating on the computerization of individual functions, such as computer aided design and shop floor control, and the integration of data relations, such as global database frameworks and distributed database management systems. A mechanism to control the information flow among all of the manufacturing application systems, in order to streamline factory activities based on company-specific and company-wide policies and procedures is proposed here. The goal is to achieve a fully integrated manufacturing management system. The INformation Systems for Integrated Manufacturing (INSIM) reflects a design methodology to build a knowledge base to serve as the control mechanism. This design methodology features an enhanced graphic modeling tool - Updated Petri Nets (UPN) - which is capable of modeling database updates and retrievals, under specific constraints and conditions, and uses a hierarchical modeling approach. Finally, a prototype rule based system, using the INSIM methodology, is being implemented. It assimilates the functionality and assertains the control of information flow between Computer Aided Design, Process Planning, Manufacturing Resource Planning and Shop Floor Control.