• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.9-17
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• 1990

This paper deals with a FOQ( ; fixed-order quantity) model for spare-part inventory control. In a spare-part inventory problem, stock depletion arises not from external market demand but from internal demand resulting from failures of parts in use. The problem differs from the classical inventory problem in that the demand for a failed part never arises more during stockout period, since the unit remains inoperative when stockout occurs until the failed part is replaced by new one. In the problem under consideration, n identical units are operating simultaneously and failed one is replaced immediately by new one if on-hand spares remain. In order to replenish spares, an order with quantity Q is placed whenever the number of on-hand spares falls to levels. The average annual cost of operating the spare-part inventory system is derived under the assumption that both lifetime of a part and replenishment lead-time distributions are exponential.

• Journal of the Korea Safety Management & Science
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• v.16 no.2
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• pp.131-138
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• 2014

Auto part industry supplies production for auto manufacturer and after market. These company have inventory for delivery. High inventory level can be good for delivery, but cost will be increase. Low inventory level can be customer unsatisfaction for delivery late. Low inventory level also is reason of low productivity by decreasing product batch size. These article suggest model for calculation a proper inventory level and prove a effect by simulation of some company.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.285-288
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• 1996

This paper deals with an (s, S) spare-part inventory model with general leadtime. In the model, if the inventory level falls to a reorder point s, a replenishment order quantity Q is ordered. Assumming that the number of operating units is one and the lifetime of a unit follows an exponential distribution, we derive the expected cost rate and suggest a procedure to obtain the optimal pair of (s, S) minimizing the cost rate.

• Korean Management Science Review
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• v.20 no.1
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• pp.77-88
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• 2003

Supply-Chain Management (SCM) was the integration of the activities that procure materials, transform them into intermediate goods and final products, and deliver them to customers. These activities include the traditional purchasing function, plus other activities that were important to the relationship with suppliers and distributors. P company was the first vendor in motor industry of Korea and had a flexible relationship with motor industry through SCM. However, p company had independent information with motor Industry and it caused many troubles In the operation of the P company. Considering these facts, authors had developed the inventory control system which was the part of order-fulfillment process and could make a progress in the operation of the inventory. The core factor of the developed inventory control system was the combination of the theoretical factors and the empirical factors. That is, the factors which were excluded in existing inventory theory revealed to be important.

• Journal of the Korean Operations Research and Management Science Society
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• v.25 no.4
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• pp.27-44
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• 2000

In this study we consider a spares provisioning problem for repairable items in which a parts inventory system is incorporated. If a machine fails, a replacement part must be obtained at the parts inventory system before the failed machine enters the repair center. The inventory policy adopted at the parts inventory system is the (S, Q) policy. Operating times of the machine before failure, ordering lead times and repair times are assumed to follow a two-stage Coxian distribution. For this system, we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of machines at each station and the probability that a part will wait at the parts inventory system. For the analysis of the proposed system, we model the system as a closed queueing network and analyze it using a product-form approximation method. A recursive technique as well as an iterative procedure is used to analyze the sub-network. Numerical tests show that the approximation method provides fairly good estimation of the performance measures of interest.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.5 no.4
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• pp.683-691
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• 2015

The purpose of this paper is to determine the actual strategies used in Inventory Management in the field of Distribution phenomenon. In the first part of the research, theoretical backgrounds will be reviewed in order to provide better understanding the importance of Inventory Management in Distribution Management. The qualitative data were gathered by face to face interviews and a phone interview from four selected intermediaries. The study finds intermediaries practicing JIT in the sales and distribution and maximizing the sales activities and minimizing the inventory cost by giving up on an opportunity cost.

• Journal of Korean Society for Quality Management
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• v.14 no.2
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• pp.21-27
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• 1986

This paper deals with a continuous review (s,S) spare part inventory system. The distributions of service life of each part and the replenishment lead time are assumed to be exponential. Assuming that there is never more than a single order outstanding, we obtain the average annual cost of operating the inventory system. If the length of stockout period is small enough to be neglected compared to the length of operating period, the optimal operating policy variables minimizing the cost rate can be calculated iteratively. For the case of one-for-one ordering (that is, s=S-1), an exact cost rate, and a closed form decision rule minimizing the cost rate are obtained for a more general situation in which more than one order is allowed to be outstanding and the distribution of the replenishment lead time is general.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.141-150
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• 2014

Due to their accessibility and 24-hr availability, convenience stores are an integral part of daily lives. Because they sell a limited number of products and have small shelf space, shelf space allocation and inventory replenishment are important considerations for inventory management that critically affect profit. In this paper, we propose five solutions for the vendor-managed inventory problem of convenience stores that maximize profit while considering stock-out-based product substitutions. The performance of the proposed solutions is evaluated via simulation to reflect the demand uncertainty and marketing activity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.47-56
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• 2012

Service Parts Management is defined as a supply management associated with service parts from the part suppliers to the final customer. A series of process to improve the customer service level by forecasting the demand and to minimize cost by maintaining the inventory level is included. Uniqueness such as missing value correction, the data pattern analysis and planned order system is designed and implemented. Main feature of order management system is to calculate order amount and order time based on selection of optimal forecasting algorithm.

• Journal of Korean Society for Quality Management
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• v.24 no.1
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• pp.44-49
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• 1996

This paper deals with a (Q, r) spare-part inventory model with gamma leadtime. In the model, if the inventory level falls to a reorder point r, a replenishment order quantity Q is ordered. Assumming that the number of operating units is one and the lifetime of a unit follows an exponential distribution, we derive the expected cost rate and suggest a procedure to obtain the optimal pair of (Q, r) minimizing the cost rate. A numerical example is presented to explain the model.