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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Item A Generative Approach for Design Evaluation and Partner Selection for Agile Manufacturing(1996) Minis, Ioannis; Herrmann, Jeffrey W.; Lam, Giang; ISRAn agile manufacturing firm forms partnerships with other manufacturers as necessary to design and manufacture a product quickly in response to a market opportunity. In order to form a successful partnership, the firm needs to create a superior design and select the partners that best fit the partnership's scope. In this paper we consider the intrinsic relationship between design evaluation and partner selection. The paper presents a generative approach that a design team can use to obtain feedback about a new product embodiment based on high- level process plans and on the manufacturing capabilities and performance of potential partners. Using this information, the design team can improve their design and identify the potential partners that best fit its manufacturing requirements. The primary application of this work is to certain types of mechanical and electronic products.Item A Practical Method for Design of Hybrid-Type Production Facilities(1994) Harhalakis, George; Lu, Thomas C.; Minis, Ioannis; Nagi, R.; ISRA comprehensive methodology for the design of hybrid-type production shops that comprise both manufacturing cells and individual workcenters is presented. It targets the minimization of the material handling effort within the shop and comprises four basic steps: (1) identification of candidate manufacturing cells, (2) evaluation and selection of the cells to be implemented, (3) determination of the intra-cell layout, and (4) determination of the shop layout. For the cell formation step the ICTMM technique has been enhanced to cater for important practical issues. The layout of each significant cell is determined by a simulated annealing (SA)-based algorithm. Once the sizes and shapes of the selected cells are known, the shop layout is determined by a similar algorithm. The resulting hybrid shop consists of the selected cells and the remaining machines. The methodology has been implemented in an integrated software system and has been applied to redesign the shop of a large manufacturer of radar antennas.Item Manufacturing Cell Formation Under Random Product Demand(1993) Harhalakis, George; Minis, Ioannis; Nagi, R.; ISRThe performance of cellular manufacturing systems is intrinsically sensitive to demand variations and machine breakdowns. A cell formation methodology that addresses, during the shop design stage, system robustness with respect to product demand variation is proposed. The system resources are aggregated into cells in a manner that minimizes the expected inter-cell material handling cost. The statistical characteristics of the independent demand and the capacity of the system resources are explicitly considered. In the first step of the proposed approach the expected value of the feasible production volumes, which respect resource capacities, are determined. Subsequently, the shop partition that results in near optimal inter cell part traffic is found. The applicability of the proposed approach is illustrated through a comprehensive examples.Item A PDES Model for Microwave Modules(1991) Bahadur, Sudhanshu; Harhalakis, George; Hosier, Robert N.; Minis, Ioannis; ISRThis paper presents a novel application of the Layered Electrical Product (LEP) model of the PDES (Product Data Exchange specification using STEP) standard. All three levels of the LEP model are developed for a typical microwave module (MWM). The latter comprises of a component layer, the artwork, an insulation layer and a ground plane, which is a complex mechanical part. The nature of the ground plane necessitated the enhancement of the first level of the model to include three dimensional topological entities. Consequently, although the artwork and insulation layers are represented in two-and-a-half dimensions, (which is common practice in the case of Printed Wiring Boards), the ground plane is modeled using the three-dimensional PDES Geometrical and Topological models and the Form Features model. Level II includes the electrical entities of the MWM. New conventions that are necessary to represent particular features of the MWM have been proposed and applied. Based on the intention of PDES, design information that is closely related to manufacturing concerns has been represented in Level III of the model. Both the proposed structure and the contents of this level for MWMs are presented. Material specifications, mechanical features, design specifications for the manufacture of joins, and others are included. Finally, potential applications of the LEP model and especially of Level III in automated process planning and producibility assessment are discussed.Item Class: Computerized LAyout Solutions Using Simulated Annealing(1990) Minis, Ioannis; Harhalakis, George; Jajodia, Satish K.; Proth, J.M.; ISRA 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.Item Manufacturing Cell Formation with Multiple, Functionally Identical Machines(1990) Minis, Ioannis; Harhalakis, George; Jajodia, Satish K.; ISRA comprehensive methodology for the formation of manufacturing cells in an environment consisting of unique as well as multiple, functionally identical machines is presented in this paper. The proposed method presupposes the existence of generic process plans that specify the types of machines required for the manufacture of each part, although more than one machine of the same type may be available in the shop. The production equipment is grouped into manufacturing cells and the manufactured parts are assigned to part families, based on an inter-cell traffic minimization criterion and subject to capacity constraints. Two or more functionally identical machines are included in a cell, only if necessitated by capacity considerations, or traffic minimization arguments. The method also considers both part set- up and run times for the evaluation of the capacity requirements, and uses pallet traffic as opposed to individual part traffic in the minimization criterion.