• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.09a
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• pp.359-359
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• 1995

• Journal of Korean Society for Quality Management
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• v.36 no.3
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• pp.102-111
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• 2008

본 연구에서는 공급리드타임이 한정된 용량을 가진 생산시스템에 의해서 내부적으로 결정되어지는 다품종 재고시스템에서의 제품의 수요변동이 미치는 영향을 조사하였다. 공급리드타임이 시스템의 외부에서 결정되어 주어지는 경우와는 달리 리드타임 수요의 변동이 제품 수요의 변동이 증가할 때 실제 감소하는 결과를 보였다. 또한, 수요의 변동이 증가할 때 전체 재고 중 안전재고의 비율이 감소되는 것도 보였다. 더 나아가서 수요 변동의 크기가 어느 정도 이상으로 커지면 안전재고가 완전히 제거되는 사실도 입증하였다. 이 같은 결과는 제품수요의 변동이 매우 클 때 리드타임 수요의 변동을 줄이기 위한 전략은 별로 효용이 없음을 보여준다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.7-14
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• 2016

Unlike most researches that focus on single manufacturer or single buyer, this research studies the cooperation policy for two participants of supply chain such as single vendor and single buyer. Especially, this paper deals with single vendor-single buyer integrated-production inventory problem. If the buyer orders products, then the vendor will start to make products and then the products will be shipped from the vendor to the buyer many times. The buyer is supposed to order again when the buyer's inventory level hits reorder point during the last shipment and this cycle keeps repeated. The buyer uses continuous review inventory policy and customer's demand is assumed to be probabilistic. The contribution of this paper is to present a mixed approach and derive its cost function. The existing policy assumes that the size of shipping batch from single vendor to single buyer is increasing, called Type 1, or constant, called Type 2. In mixed approach, the size of shipping batch is increasing at the beginning part of the cycle, and then its size is constant at the ending part of the cycle. The number of shipping for Type 1 and Type 2 in a cycle in mixed approach is determined to minimize total cost. The relationship between parameters, for example, the holding cost per product, the set up cost per order, and the shortage cost per item and decision variables such as order quantity, safety factor, the number of shipments, and shipment increasing factor is figured out via sensitivity analysis. Finally, it is statistically proved that the mixed approach is superior to the existing approaches.

• Industrial Engineering and Management Systems
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• v.14 no.4
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• pp.401-412
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• 2015

In this paper, we present a modeling approach to production planning for an actual production line and a heuristic method. We also illustrate the successful implementation of the proposed method on the production line. A heuristic algorithm called the push-back algorithm was designed for a single machine earliness/tardiness production planning with distinct due date. It was developed by combining a minimum slack time rule and shortest processing time rule with a push-back procedure. The results of a numerical experiment on the heuristic's performance are presented in comparison with the results of IBM ILOG CPLEX. The proposed algorithm was applied to an actual case of production planning at Woongjin Chemical, a leading manufacturer of filter products in South Korea. The seven-month execution of our algorithm led to a 24.5% decrease in the company's inventory level, thus demonstrating its practicality and effectiveness.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.237-244
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• 2018

The Smart Factory level of manufacturing factories of SMEs now lacks a system for grasping the accurate inventory amount associated with inventory movements in managing warehouses at the basic level. Also, it is difficult to manage accurate materials for loss of data due to worker manual work and production method due to experience. In order to solve this problem, in this paper, automatic acquisition of inventory to minimize manual work to grasp workers' Inventory and improve automation is done. In the smart warehouse management system using the IoT-based autonomous mobile module, the autonomous mobile module acquires the data of the inventory storage while moving through the line. In order to grasp the material of the Inventory storage, The Camera module recognizes the name of the inventory storage. And Then, If output matches, the data measured by the sensor is transferred to the server. This data can be processed, saved in a database, and real-time inventory quantity and location can be grasped in a web-based monitoring environment for administrators. The Real-time Automatic Inventory (RAIC) systems is reduce manual tasks and expect the effects of automated inventory management systems.

• Industrial Engineering and Management Systems
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• v.6 no.1
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• pp.1-10
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• 2007

The objective of this study is to develop an optimal joint cost from the perspectives of both the manufacturer and the retailer. The integrated production-inventory model with Weibull distribution deteriorating items is assumed to have a constant demand rate. A limited retailer storage space and multiple delivery per order are considered in this model. A numerical example including the sensitivity analysis is given to validate the results of the production-inventory model.

• The Journal of Information Systems
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• v.12 no.2
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• pp.129-149
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• 2003

One of the important applications in Enterprise Resource Planning(ERP) systems is the Manufacturing Resource Planning(MRPII) system using Bill of Material(BOM). The manufacturing resource planning determines the quantity and timing of the production or purchase of subassemblies and raw materials needed to support the Master Production Scheduling(MPS). The bill of material is the recipe, a list of the materials needed to make a product. This paper intends to suggest a component-based materials management system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based materials management systems designed with UML methodology, we analyzed the workflow and the document on materials management process from production planning to inventory management, and implemented a prototype of efficient materials management system, as a surrogate of existing material requirement planning(MRPI) system. To produce many other assemblies for a automobile part firm, component parts are assembled into subassemblies that are joined to assemble the finished product. Through the system suggested in this study, the level of inventory has cut down and the cost of inventory management has decreased. Also, the development method using UML makes the analysis and design phase to shorten in implementation period of MRPII system. The implementation of materials management system using CBD shows the ease of use in software reuse and the interoperability with corporate Internal information system. The result of applying object-oriented CBD technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.1
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• pp.64-71
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• 2005

The purpose of this study is to propose guidelines for introducing the Just-In-Time (JIT) production system to enhance the competitiveness of Korean manufacturing companies. This study employed an extensive survey on the use of the JIT production systems among different korean manufacturing companies to understand the current status of the JIT production system in use and to identify the benefits from implementing JIT production system. The survey has covered 170 manufacturing companies of different sizes from various sectors of Korean industries including electronics, automobiles, machineries, and textiles. In conclusion, our research results support that the JIT production system would contribute to increase the manufacturing performances of Korean manufacturing companies through lower inventory level and increased quality level.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.398-405
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• 1997

This article presents a new model which is called Periodic Square-Wave(PSW) to describe the material flow of the periodic processes involving intermediate buffer. The material flows incoming into and outgoing from the intermediate buffer are assumed to be periodic square shaped. PSW model gives the same result as that of Economic Production Quantity(EPQ) model for determining optimal lot size of single stage batch storage system. However, for batch storage serial train system, PSW model gives a different optimal solution of about 6 % reduced total cost. PSW model provides the more accurate information on inventory and production system than the classical approach by maintaining simplicity and increasing computational burden.

• IE interfaces
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• v.18 no.3
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• pp.350-360
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• 2005

This paper considers a strategy for planning of rework in semiconductor monitoring burn-in test process. The equipment error in monitoring burn-in test process generates many defects. These defects are transformed into good products by rework process, i.e. retest. Rework has the advantage of saving production costs. But rework increases holding costs and incurs rework costs. In monitoring burn-in test process, rework depends on operator's experience with no pre-defined specification. In practice, a number of rework activities are performed with respect to the product importance and inventory quantity. Moreover, disregard for order jobs schedule have caused due date penalties. So a strategy for planning of rework by which order jobs schedule are not affected is suggested. Futhermore, production costs, rework costs and inventory costs for planning of rework are considered.