• 한국산학기술학회논문지
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• 제3권2호
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• pp.120-125
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• 2002

본 논문은 전자상거래의 발전으로 인해 더욱 그 중요성이 부각되고 있는 중간창고(데포)에서의 발주시스템에 관한 연구이다. 제안 모델의 특징으로는 종래의 발주점 개념에서 발주범위라는 새로운 개념을 도입한 것이다. 제안 모델에서는 종래의 발주점 방식에서 고려하지 못 했던 다품종 발주와 발주시 적재효율을 고려한 수송조건 등을 포함하여 정식화하고 모델의 해법을 제안하고 있다. 또한 수치 예를 통하여 제안 모델의 유용성을 보여주고 있다.

• 대한산업공학회지
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• 제34권1호
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• pp.1-12
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• 2008

The Kanban system in Just-In-Time (JIT) production is very effective in reducing the inventories when consumption rate of the final product is relatively stable. When large fluctuations exist in the consumption rate, a new production ordering policy in which the production order quantity is determined by smoothing the demands exponentially is more suitable. This new ordering policy has not been investigated sufficiently. In this research, a multi-stage production and inventory system with stock points for materials and finished items located at each stage is considered. Approximations of average inventories at each stage in the system are derived theoretically. Numerical simulations are carried out to assess the accuracy of approximations and to evaluate the effectiveness of the new ordering policy as compared with the Kanban system. As a result, it is shown that the new ordering policy can achieve significantly lower inventory costs than the original Kanban system. The new ordering policy thus emerges as a key concept for an effective supply chain management.

• 한국산학기술학회논문지
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• 제7권2호
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• pp.251-256
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• 2006

본 논문은 다단계, 다품종 조립라인을 고려한 모델이며 JIT 생산시스템에서의 최적의 발주량 계산을 목적으로 하고 있다. 제안 모델의 목적함수는 재고비와 setup 비의 합이 최소화되도록 설계되어 있다. 이는 대부분의 자동차 부품회사의 경우 setup 공정을 포함하고 있기 때문이다. 마지막으로 수치실험을 통해 제안 모델의 유효성을 보여 주고 있다.

• Industrial Engineering and Management Systems
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• 제7권3호
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• pp.257-265
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• 2008

This paper deals with the joint decisions on pricing and ordering for a monopolistic retailer who sells perishable goods with a fixed lifetime or demand period. The newsvendor-typed problem is formulated as a two-period inventory system where the first period represents the inventory of fresh or new-arrival items and the second period represents the inventory of items that are older but still usable. Demand may be for either fresh items or for somewhat older items that exhibit physical decay or deterioration. The retailer is allowed to adjust the selling price of the deteriorated items in the second period, which stimulates demand and reduces excess season-end or stale inventory. This paper develops a stochastic dynamic programming model that solves the problem of preseason decisions on ordering-pricing and a within-season decision on markdown pricing. We also develop a fixed-price model as a benchmark against the dual-price dynamic model. To illustrate the effect of the dual-price policy on expected profit, we conduct a comparative study between the two models. Extension to a generalized multi-period model is also discussed.

• 산업경영시스템학회지
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• 제10권16호
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• pp.129-132
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• 1987

Multi-item inventory problems can be well characterized by the nature of interaction of the quantities and timing. This interaction may be due to the effect of certain combination of orders. It is that the set-up cost of ordering individual items can be saved by jointly ordering at a time. This study finds a decision criteria of optimum inventory policy through the comparisons of individual multi-item order policy(IMP), joint multi-item order policy(JMP), augmented multi-item order policy(AMP) in cost ratio. Subsequently we assume that there exists a unique optimum order level corresponding to an optimum reorder range for the augmented multi-item order, at which a cost saying is maximum.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2002년도 춘계학술발표논문집
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• pp.87-89
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• 2002

본 연구는 전자상거래의 발전으로 인해 더욱 그 중요성이 부각되고 있는 중간창고(대포)에서의 반주시스템에 대한 새로운 개념을 도입한 모델을 제안하고 있다. 제안 모델은 종래의 발주점방식과 비교되는 발주범위에 의한 발주방식이며, 발주시 수송조건을 고려하고 있다. 본 논문에서는 모델의 정식화가 해법을 제안하고 있으며 수치 예를 통하여 그 유용성을 보여주고 있다.

• 한국경영과학회지
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• 제25권4호
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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.