• 산업공학
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• 제17권spc호
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• pp.52-61
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• 2004

During the past decades automated storage/retrieval (AS/R) systems have been dominantly implemented in most industrial fields due to their handling efficiency and high utilization of storage space. Such AS/R systems consist of several modules each of which contains two racks and a S/R machine. This paper proposes a design of the hybrid AS/R module which can be adopted without too much initial expenditure by most of small-and-medium sized companies. The hybrid module consists of an AS/R module on the upper floor and a traditional warehouse module on the lower floor. For the AS/R module, analytical expressions of the expected travel times for the S/R machine and the elevator per operation are derived. The expected travel times represent the performance of the module and thus can be used for its economic design.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.47-48
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• 2008

• 대한산업공학회지
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• 제24권4호
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• pp.579-589
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• 1998

Full turnover-based storage policy (FULL) is often used to minimize the travel time needed to perform storage/retrieval operations in automated storage/retrieval systems (AS/RSs). This paper presents an approach for determining the required storage capacity for a unit load AS/RS under the FULL. An analytic model is formulated such that the total cost related to storage space and space shortage is minimized while satisfying a desired service level. To solve the model, some analytic properties are derived and based on them, an iterative search algorithm which always generates optimal solutions is developed. To illustrate the validity of the approach, an application is provided when the standard economic-order-quantity inventory model is used.

• 대한산업공학회지
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• 제21권2호
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• pp.239-254
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• 1995

Automated Storage/Retrieval (AS/R) systems have been used mostly in manufacturing or distribution industry in order to store or retrieve palletized items automatically. Since the items ore heavy or bulky, only one pallet at a time is moved by the stacker crane In this study, however, we introduce the "multi -load" AS/R system in which the items to be stored are data storage devices of equal size such as video tape or compact disc. Since the items are small and light multiple items can be stored and retrieved in each trip by using a magazine and a robot arm mounted on the crane Given the magazine capacity, and the locations of retrieval items and empty cells in the rack, the throughput of the multi-load AS/R system will depend on the selection of storage locations and the sequence of visits. We propose four heuristic algorithms for the multi-command. Computer simulation is used to evaluate the four algorithms in terms of throughput and number of back tracking of the crane.

• 산업공학
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• 제11권1호
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• pp.131-143
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• 1998

Automated Storage/Retrieval Systems(AS/RS) are widely utilized to increase the efficiency of logistics system. In this paper, to offer the basic data required for the standardization and automation of AS/RS, we look into the conditions of several domestic AS/RS manufacturing companies and examine the national and international market conditions and the technical levels of domestic companies. And also, for the domestic companies, government departments and logistics related organizations, we survey and analyze the present state for the installation, implementation and operation of AS/RS and the related equipment systems, and the degree of recognition for the relational aspects.

• 산업공학
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• 제3권2호
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• pp.39-51
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• 1990

One of the most important and powerful tools available for design and/or study of the operation of complex systems and processes is simulation. Since automated material handling systems like AS/RS are often quite complex, a network-based simulation model is developed to analyze an automobile part supplier's automated storage and retrieval system(AS/RS). The network simulation model is implemented in the SLAM Ⅱ on a VAX 8800 computer. Performance of the AS/RS was tested for 3 dispatching rules, 3 work load levels, 2 storage policies, 3 levels of stacker crane break-down, and 2 conveyor system layouts. Results indicate that the AS/RS performance is primarily affected by the dispatching rule and work load level.

• 한국경영과학회지
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• 제13권2호
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• pp.34-46
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• 1988

This paper deals with design problem of unit load automated storage/retrieval systems (AS/RS). We propose an optimal design model in which the investment and maintenance costs of AS/RS, operating under dual command model is minimized over a time horizon satisfying the warehouse dimensional constraints. The model is formulated as an integer nonlinear program and an algorithm is proposed to find an optimum solution. The valididty of the solution algorithm is illustrated through an example.

• 산업경영시스템학회지
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• 제46권1호
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• pp.68-75
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• 2023

In an automotive plant, an automated storage and retrieval system (ASRS) synchronizes material handling flows from a part production line to an auto-assembly line. The part production line transfers parts on small-/large-sized pallets. The products on pallets are temporarily stored on the ASRS, and the ASRS retrieves the products upon request from the auto-assembly line. Each ASRS aisle is equipped with narrow-/wide-width racks for two pallet sizes. An ASRS aisle with narrow-/wide-width racks improves both storage space utilization and crane utilization while requiring delicate ASRS aisle design, i.e., the locations of the narrow-/wide-width racks in an ASRS aisle, and proper operation policies affect the ASRS performance over demand fluctuations. We focus on operation policies involving a common storage zone using wide-width racks for two pallet sizes and a storage-retrieval job-change for a crane based on assembly-line batch size. We model a discrete-event simulation model and conduct extensive experiments to evaluate operation policies. The simulation results address the best ASRS aisle design and suggest the most effective operation policies for the aisle design.

• 한국생산제조학회지
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• 제23권5호
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• pp.505-511
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• 2014

The functional role of warehouses in modern industry is changing from an established concept of storage to a concept of circulation. The target of this study is to improve the stacker crane's efficiency for the internal operations of the Automated Storage and Retrieval System (AS/RS). Eight operating schemes are proposed under the combination of three conditions, namely, the storing method, the layout type, and the sequence of command execution. The moving distance of the stacker crane is calculated using the same gateway data through a simulation based on a C# program. The optimal operating scheme is proposed based on the analyzed simulation results. In conclusion, the combination of conditions of random storage, two-way type warehouse, and dual command execution elicits optimum results in travel efficiency for the stacker crane.

• 대한산업공학회지
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• 제22권2호
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• pp.179-188
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• 1996

We study n-class-based storage policy for an automated storage/retrieval system (AS/RS) and derive the closed form expressions of expected travel times under single command cycle. In order to confirm the correctness of the derivations, we consider both discrete and continuous storage racks, and show that the expressions for expected travel times of discrete rack converge to those of continuous one. We also derive the expected travel times when the coordinate locations for storages or retrievals are triangularly distributed and we try to solve class layout problem using the obtained results. Numerical examples are given in case of 3-class-based storage policy.