• IE interfaces
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• v.18 no.2
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• pp.136-147
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• 2005

This paper introduces a simulation study regarding the operation of the Painted Body Storage (PBS) in an automobile factory. In the paint shop of the factory, same colored bodies are grouped together in order to increase the effectiveness of process, for example decrease the loss of cleaning the painting-gun when the color of body changes from one to another. However the production of automobiles in the assembly shop is a typical example of the mixed model assembly production. Therefore PBS locates between the paint shop and the assembly shop for control the input sequence of bodies to the assembly shop, and it enables to meet the smoothing requirement of assembly sequence. There are highly restricted constraints on the assembly sequence in a assembly shop. Those are spacing restriction and smoothing restriction. If such restrictions are violated, conveyor-stop or utility work will be necessary. Thus the major objective of PBS is to control the assembly sequence in a way to meet the two restrictions. In this paper a case study of PBS in an automotive factory is introduced. The storage/retrieval algorithms are suggested and the proposed system is verified using simulation models. Sensitivity analysis for operating factors is also conducted.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.310-313
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• 1996

Mathematical programming method for finding optimal solution of job shop scheduling is inadequate to real situation because fo too much computation time. In contrast, dispatching rule is helpful for reducing compuation time but is not guaranted to find optimal solution. The purpose of this paper is to develop a new dispatching rule and procedure to minimize mean flow time whose result is near the optimal solution for job shop scheduling. First step is to select machine which have shortest finishing operation time among the schedulable operations. Second step is to select operation with regard to estimated remaining operation time. The suggested rule is compared with nondelay and MWKR rule for three examples, and is confirmed to be most effective to minimize mean flow time.

• IE interfaces
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• v.14 no.1
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• pp.59-66
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• 2001

This paper introduces the case study that has been performed at the block paint shop, Hyundai Heavy Industries. First of all, the overall production processes of shipbuilding and research activities conducted by Korean are reviewed with a view-point of production planning. Then HYPOS(Hyundai heavy industries Painting shop Operation System) project is briefly described, which has several modules such as planning module, scheduling module, work order module, and DB(database) management module. Although the HYPOS system has several modules, this paper mainly focuses on the planning module that utilizes the rough-cut simulation algorithm to make a decision about the policy for production schedule. The HYPOS has been operated since June, 2000 and the operation data has been collected for the purpose of future evaluation about the performance of HYPOS system. The evaluation of HYPOS will be shown in a public domain as soon as the enough operation data is available.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.05a
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• pp.429-434
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• 2002

For companies assembling end products from sub assemblies or components, MRP (Material Requirement Planning) logic is frequently used to synchronize and pace the production activities for the required parts. However, in MRP, the planning of operational-level activities is left to short term scheduling. So, we need a good scheduling algorithm to generate feasible schedules taking into account shop floor characteristics and multi-level job structures used in MRP. In this paper, we present a GA (Genetic Algorithm) solution for this complex scheduling problem based on a new gene to reflect the machine assignment, operation sequences and the levels of the operations relative to final operation. The relative operation level is the control parameter that paces the completion timing of the components belonging to the same branch in the multi-level job hierarchy. In order to revise the fixed relative level which solutions are confined to, we apply large step transition in the first step and GA in the second step. We compare the genetic algorithm and 2-phase optimization with several dispatching rules in terms of tardiness for about forty modified standard job-shop problem instances.

• Industrial Engineering and Management Systems
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• v.15 no.1
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• pp.11-18
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• 2016

This paper considers a scheduling problem in a flexible job shop with a reconfigurable manufacturing cell. The flexible job shop has both operation and routing flexibilities, which can be represented in the form of a multiple process plan, i.e. each part can be processed through alternative operations, each of which can be processed on alternative machines. The scheduling problem has three decision variables: (a) selecting operation/machine pairs for each part; (b) sequencing of parts to be fed into the reconfigurable manufacturing cell; and (c) sequencing of the parts assigned to each machine. Due to the reconfigurable manufacturing cell's ability of adjusting the capacity, functionality and flexibility to the desired levels, the priority scheduling approach is proposed in which the three decisions are made at the same time by combining operation/machine selection rules, input sequencing rules and part sequencing rules. To show the performances of various rule combinations, simulation experiments were done on various instances generated randomly using the experiences of the manufacturing experts, and the results are reported for the objectives of minimizing makespan, mean flow time and mean tardiness, respectively.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.4
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• pp.173-189
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• 2015

The purpose of this study is to present the classification and operation systems of fashion offline stores. This research analyzed fashion literatures, articles and papers published by fashion-related companies and interviewed fashion practitioners. This research can be used as information for practitioners of the domestic fashion brand and students of fashion majors. The classification and operation systems of fashion offline stores are as follows. 1. The types of fashion offline store is classified as a form of road shop, department store, complex shopping center, select shop, outlet, and fashion wholesale retail specialty store. 2. The road shop is classified flagship store, franchise store, direct sales store, and street brand store. 3. The department store is recently using strategy to improve the profit rate, as setting up the select shop, expand the import contemporary brand stores, the men's brand stores, SPA brand stores, the street brand stores, and the soho internet shopping mall brands instead of reducing the national brands. 4. Most forms of fashion offline stores enhanced the functions to combine the catering, cultural activities and purchasing the lifestyle-related products, as well as fashion items. 5. The types of the operation system in fashion offline stores is classified as direct operations, franchise operations, middle management operations, and fully insert operations. 6. Franchise operations are tended to decline, however middle manager operations are overwhelming.

• Korean Journal of Computational Design and Engineering
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• v.10 no.4
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• pp.237-243
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• 2005

To increase the productivity and efficiency of an enterprise, all relevant product information should be provided to shop floor workers timely and in a unified form because shop floor workers are final consumers of most accumulated information generated from various departments of an enterprise. But, most existing enterprise information systems have an emphasis upon providing design/manufacturing information to office workers. Proposed in this study is the development of integrated design/manufacturing information system focused on providing cohesive information required to shop floor activities. For developing integrated information system, the functional requirements at the shop floor are identified and analyzed. Based on the extracted functional requirements, object-oriented system design and implementation is conducted. By using this system, shop floor workers can use all relevant information required to their daily operation in a integrated and unified form.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.208-215
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• 1995

Numerous solution methods for scheduling problems such as part dispatching problem, operation sequence problem have been suggested as a means to be embedded in hierarchical or centralized shop floor control. Under the preceding control philosophies, however, response to changes in the shop floor status is quite slow and timely decision is sometimes impossible. Moreover, the control software becomes too large and it is almost impossible to modify the control software when the configuration of the shop floor changes. In agile manufacturing which emerged recently to cope with quick response and easy modifiability when unexpected changes occur, a new control policy is needed. CSCW[Computer Supported Cooperative Work] based shop floor control casts a different view on scheduling problems. Decisions are made locally when requested and useful information is scattered among agents for its efficient use. Adaptation is easy because agents are -'plug compatible or portable. In this paper, scheduling problems occurring under CSCW based shop floor control are identified and characterized. Traditional scheduling problems are reviewed from the CSCW viewpoint. All the control entities involved in the shop floor can be found and used to defined agents. With these entities and CSCW concept, possible scheduling problems are identified.

• International Journal of Quality Innovation
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• v.6 no.3
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• pp.70-94
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• 2005

The IC packaging industry heavily relies on shop floor information, necessitating the development of a model to flexibly define shop floor information and timely handle manufacturing data. This study presents a novel data model of product manufacturing flow to define shop floor information to effectively respond to accelerated developments in IC package industry. The proposed data model consists of four modules: operation template setup, general process setup, enhanced bill of manufacture (EBOMfr) setup, and work-order process setup. The data model can flexibly define the required shop floor information and decision rules for shop floor product manufacturing flow, allowing one to easily adopt changes of the product and on the shop floor. However, to handle floor dynamics of the IC packaging industry, this work also proposes a WIP (i.e. work-in-process) system for monitoring and controlling the product manufacturing flow on the shop floor. The WIP system integrates the data model with a WIP execution module. Furthermore, an illustrative example, the MIRL WIP System, developed by Mechanical Industrial Research Laboratories of Industrial Technology Research Institute, demonstrates the effectiveness of the proposed model.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.3
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• pp.409-428
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• 1995

Job shop scheduling with m different machines and n different jobs is a NP-hard problem of combinatorial optimization. The purpose of the paper is to develop the heuristic method using tabu search for job shop scheduling to minimize makespan or mean flowtime. To apply tabu search to job shop scheduling problem, in this paper we propose the several move methods that employ insert moves in order to generate the neighbor solutions, and present the efficient rescheduling procedure that yields active schedule for a changed operation sequence by a move of operations. We also discuss the tabu search techniques of diversifying the search of solution space as well as the simple tabu search. By experiments, we find the appropriate tabu list size and tabu attributes, and analyze the proposed tabu search techniques with respect to the quality of solutions and the efforts of computation. The experimental results show that the proposed tabu search techniques using long-term memory function have the ability to search a good solution, and are more efficient in the mean flowtime minimization problem than in the makespan minimization.