• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.167-174
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• 2008

본 연구는 공급자, 중간분배자 그리고 고객으로 구성된 2 단계 공급사슬에서 시간에 따라 일정률로 퇴화하는 퇴화성 제품을 취급하는 중간분배자의 경제적 재고모형을 분석하였다. 문제 분석을 위하여 공급자는 고객으로부터의 수요를 증대시키기 위한 수단으로 일정한 묶음 단위별로 일정한 양의 덤을 제공한다는 가정 하에 재고모형을 설계하였고, 모형 분석을 통하여 이익을 최대화하는 경제적 주문량 결정 방법을 제시하였다. 또한 예제를 통하여 제시된 해법을 적용하고, 그 타당성을 보였다.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.3
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• pp.232-239
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• 2002

This paper analyzes how a buyer can determine the economic replenishment policy when the supplier allows delay in payments for an order of a product. For the analysis, it is assumed that the length of credit period is a function of the buyer's amount of purchase, and inventory is depleted not only by buyer's demand but also by deterioration. Investigation of the properties of the model developed allows us to develop an algorithm whose validity is illustrated using an example problem.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.279-287
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• 2015

본 연구는 공급자(supplier), 중간공급자(distributor) 그리고 고객(customer)으로 구성된 2 단계 공급사슬에서 퇴화성 제품(deteriorating products)에 대한 중간공급자의 재고모형을 분석하였다. 문제 분석을 위해 공급자는 중간공급자의 수요 증대를 목적으로 중간공급자의 주문 크기에 따라 차별적으로 외상 기간을 허용하고, 최종 고객의 수요는 중간공급자의 재고 수준에 따라 선형적(linearly)으로 증가한다는 가정 하에 모형을 분석하였다. 중간공급자의 이익을 최대화하는 경제적 주문량 결정 방법을 제시하였고, 예제를 통하여 그 해법의 타당성을 보였으며, 민감도 분석을 통하여 퇴화율이 재고정책에 미치는 영향을 분석하였다.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.271-276
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• 2021

In this paper we analyze the effect of the credit period on inventory policy under trade credit with ordering cost including a fixed cost and freight cost, where the freight cost has a quantity discount. For marketing purposes, some supplier offers credit period to his buyer to stimulate the demand for the product he produces. The delay in payments during the credit period has the effect of reducing the buyer's capital opportunity cost. It is also assumed that the buyer pays the freight cost for the order and hence, the ordering cost consists of a fixed ordering cost and a variable freight cost which depends on the order quantity. As a result, the possibilities of trade credit and discounts on freight costs are expected to play an important role in the buyer's inventory policy. Based on the economic order quantity inventory model, we analyze how the buyer can determine the optimal inventory policy and we examine the effect of the length of credit period on the buyer's inventory policy.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.353-360
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• 2019

Trade credit is being used as a price discrimination strategy by the suppliers in order to increase the customer's demand. From the viewpoint of the customer, if delayed payment is allowed for a certain period of time from the supplier, the effect of reducing the inventory carrying cost will positively affect the customer's order quantity. Also, in deriving the economic order quantity(EOQ) formula, it is tacitly assumed that the customer's ordering cost is a fixed cost. However in many business transactions, the customer pays the freight cost for the transportation of his order and so, the customer's ordering cost contains not only a fixed cost but also a freight cost which is a function of the order size. Therefore, in this study, we analyzed the inventory model which considers that the customer's ordering cost contains not only a fixed cost but also a freight cost which is a function of the customer's order size when the supplier permits a delay in payments. For the analysis, it is also assumed that inventory is exhausted not only by customer's demand but also by deterioration. Investigation of the properties of an optimal solution allows us to develop an algorithm whose validity is illustrated using an example problem.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.485-491
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• 2022

The traditional economic order quantity (EOQ) model is analyzed under the basic assumption that the purchase price is paid immediately upon receiving the product. However, product suppliers may allow a certain period of deferral of payment for product purchase costs in order to differentiate themselves from competitors. From the distributor's point of view, such a credit transaction can temporarily divert product purchase costs, resulting in a reduction in inventory investment costs, and ultimately, a factor that lowers the selling price for the purpose of increasing end-customer demand can be. In addition, in that credit transactions are provided for the purpose of increasing the demand of suppliers as a means of differentiation from competitors, it is more general to be allowed flexibly according to the transaction volume. In this regard, assuming that the end customer's demand is represented by a linear decreasing function of the distributor's selling price, this study analyzes a model for determining the distributor's pricing and ordering policies under order-size-dependent delay in payments. For the analysis, we also assume that the inventory is depleted not only by customer's demand but also by decaying.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.62-70
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• 2020

As an effective means of price discrimination, some suppliers offer trade credit to the distributors in order to stimulate the demand for the product they produce. The availability of the delay in payments from the supplier enables discount of the distributor's selling price from a wider range of the price option in anticipation of increased customer's demand. Since the distributor's lot-size is affected by the demand for the customer, the distributor's lot-size and the selling price determination problem is interdependent and must be solved at the same time. Also, in many common business transactions, the distributor pays the shipping cost for the order and hence, the distributor's ordering cost consists of a fixed ordering cost and the shipping cost that depend on the order quantity. In this regard, we deal with the joint lot-size and price determination problem when the supplier allows delay in payments for an order of a product. The positive effects of credit transactions can be integrated into the EOQ (economic order quantity) model through the consideration of retailing situations, where the customer's demand is a function of the distributor's selling price. It is also assumed that the distributor's order cost consists of a fixed ordering cost and the variable shipping cost. We formulate the distributor's mathematical model from which the solution algorithm is derived based on properties of an optimal solution. A numerical example is presented to illustrate the algorithm developed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.63-72
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• 1992

본 연구의 목적은 교환기 및 가입자 선로에 대한 투자계획의 수립 즉 적정수준의 공급주기와 공급량을 산정하는 방안을 모색해 보는 것이다. 이와 같은 연구를 수행하기 위하여 우선 한국통신의 공급계획수립업무에 대한 현황파악과 함께 한국통신의 공급계획수립에 적용할 수 있는 이론적 모형을 다각도로 검토해 보았다. 그 결과 재고모형이 가장 적합하다고 판단되어 재고모형의 여러 대안을 현행 공급계획수립방법과 비교하여 공급주기와 총비용을 비교분석하였다. 본 연구에서는 Economic Order Quantity(EOQ)모형, Dynamic Lot Size(DLS)모형, 그리고 Simulation이 분석의 도구로 사용되었으며, Simulation은 두가지 방법을 적용하였다. 첫번째 방법은 개별 전화국을 대상으로 simulation을 실시하여 최소의 비용을 보이는 공급주기를 각 전화국별로 산정하는 것이며, 두번째 방법은 모든 전화국에 동일한 공급주기를 적용하여 개별 전화국에서 발생하는 비용의 총합계가 최소화되는 공급주기를 산정하는 것이다. 각 대안별로 공급주기와 총비용을 산정해 본 결과 교환기의 경우는 총비용면에서 현행방법과 본 연구에서 제안한 대안들간에 커다란 차이는 없었으나, 모든 전화국에 동일한 공급주기를 일률적으로 적용시키는 것보다 각 전화국의 수요증가형태에 맞는 공급주기를 별도로 산정하여 적용시키는 것이 보다 경제적이었다. 한편, 가입자선로의 경우는 본 연구에서 제시한 대안들이 현행방법에 비해 연간 수백억원에 이르는 투자지출을 절감 할 수 있음을 보였다.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.246-253
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• 2007

All of the machines in a production line can be classified into bottleneck and non-bottleneck machines. A bottleneck is a resource whose capacity limits the throughput of the whole production facility. This paper addresses a batch sizing problem at the bottleneck machine. Traditionally, most batch sizing decisions have been made based on the EOQ (economic order quantity) model where setup and inventory costs are considered while throughput rate is assumed to be given. However, since batch size affects the capacity of the bottleneck machine, the throughput rate may not be constant. As the batch size increases, the frequency of the setup decreases. The saved setup time can be transferred to processing time, which results in higher throughput. But, the larger batch size may also result in longer lead time and larger WIP inventory level. This paper presents an alternative method to determine batch size at the bottleneck machine in a manufacturing line. A linear search algorithm is introduced to find optimal throughput rate and batch size at the same time. Numerical examples are provided to see how the proposed method works and to investigate the effects of some parameters.