• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2007.05a
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• pp.198-208
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• 2007

Recently business enterprises have forced to face in fierce competition in today's global markets due to the short life cycles of products and the higher expectation of customers. Together with continuing advances in communications and transportation technologies, these environments have motivated the continuous evolution of the supply chain and the management techniques. This paper consider three-echelon inventory system which consist of one manufacturer, one distributor and N retailers for a single product under assumption of constant demand. This paper propose the inventory replenishment period using heuristic method and order policy through coordination of inventory replenishment period. The simulation results show that decrease the total cost of the three-echelon inventory system.

• The Journal of Society for e-Business Studies
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• v.6 no.3
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• pp.1-16
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• 2001

In this paper, we introduced a POS(Point of Sale) system for a wallpaper company. We designed the database schema for the POS system, and proposed various application areas of the POS system. Especially, we discussed such application areas as inventory control, marketing, product development, and distribution channel. The quality of product management is enhanced by precise ABC inventory control and safety stock control. Marketing strategies can be more precisely established, and their effects can be measured. The development time can be shortened and new products can be developed based on the real market demands. Distributors can improve their management quality using precise sales data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.236-246
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• 2008

We consider the Inventory Routing problem(IRP) for the vending machine operating system. An artificial immune system(AIS) is introduced to solve the IRP. The IPR is an rolling wave planning. The previous solution of IRP is one of good initial solution of current IRP. We introduce an Artificial Immune system with memory cell (AISM) which store previous solution in memory cell and use an initial solution for current problem. Experiment results shows that AISM reduced calculations time in relatively less demand uncertainty.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.165-171
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• 2014

We develop an optimization algorithm for a periodic review inventory system under a stochastic budget constraint. While most conventional studies on the periodic review inventory system consider a simple budget limit in terms of the inventory investment being less than a fixed budget, this study adopts more realistic assumption in that purchasing costs are paid at the time an order is arrived. Therefore, probability is employed to express the budget constraint. That is, the probability of total inventory investment to be less than budget must be greater than a certain value assuming that purchasing costs are paid at the time an order is arrived. We express the budget constraint in terms of the Lagrange multiplier and suggest a numerical method to obtain optional values of the cycle time and the safety factor to the system. We also perform the sensitivity analysis in order to investigate the dependence of important quantities on the budget constraint. We find that, as the amount of budget increases, the cycle time and the average inventory level increase, whereas the Lagrange multiplier decreases. In addition, as budget increases, the safety factor increases and reaches to a certain level. In particular, we derive the condition for the maximum safety factor.

• Journal of the Korea Society for Simulation
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• v.24 no.1
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• pp.1-8
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• 2015

This research focuses on the method of inventory management to find out the best way in various SCM. There are several comparable methods of inventory management like Min-Max, regular interval, fixed target inventory that have different lead-time and demand for each product. Also, the inventory performances between the case of three-stages and two-stages in SCM are analyzed. 8 scenarios for the simulation are suggested considering order ways and stages. Input data for the simulation is from the result of the previous studies and actual data in the market. The performance measurements are selected as sales revenue, total number of sales, total delivery cost, total inventory shortages, the number of inventory shortage occurrence, the loss for inventory shortages, average inventory, handling cost, net profit. According to the results of the simulation, fixed target inventory management is better than existing inventory management method by net profit and inventory and so on. Also, it was confirmed that the increase in profit is obtained when SCM stages is reduced from three-stages to two-stages in existing SCM. The result of the research provides significant meaning that newly introduced target inventory management system shows good performance and SCM performance can be improved by reducing the stages.

• 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.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.11a
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• pp.101-105
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• 2002

In a traditional hierarchical inventory system, direct orders are the only information for inventory management that is exchanged between the firms involved. But due to the rapid development of modern information technology, it becomes possible for the firms to share more information in real time, e.g. demand and inventory status data. And so the term Supply Chain has emerged because it is seen as an important source of competitive advantage. Now it is possible to challenge traditional approaches to inventory management. In the past, one of the de-facto assumptions for inventory management was that the demand pattern follows a specific distribution function. However, it is undesirable to apply this assumption in real situations because the demand information in the supply chain tends to be distorted due to the bullwhip effect in a supply chain. To overcome this weakness, we propose a new solution method using NN (Neural Network). Our method proceeds in three steps. First, we find the patterns of optimal reorder points by analyzing past data. Second. train the NN using these pattern data and finally decide the reorder point. Using simulation experiment, we show that the proposed solution method gives better result than that of traditional research.

• Proceedings of the Safety Management and Science Conference
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• 2010.04a
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• pp.107-116
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• 2010

Government and company are unfolding greenhouse gas reduction activity to prevent the effects of global warming. Also, verification business through greenhouse gas inventory construction is spreaded variously. Greenhouse gas verification proceeds by document examination, risk analysis, field survey. Document investigates emission information, calculation standard, emission report, data management system. And through risk assessment result, establish field verification plan. Through study on risk assessment of greenhouse gas inventory verification, wish to reduce risk of verification.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.1
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• pp.36-43
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• 2013

Many retailer store managers are experiencing the situation where some customers balk at purchasing products if the stock is low. In this paper, we extend the single period newsvendor model in an environment of customer balking behavior occurring at double threshold inventory levels assuming the chance of sales during balking is a discrete function of inventory level. Our analysis is based on the assumption that only the mean and the variance of demand are known, without assuming any specific distributional form. We derive the explicit general expression of optimal order quantity with unknown distribution of demand with double threshold inventory levels of customer balking. Then, we illustrate the concepts developed here through simple numerical examples and conclude the future research topics under balking situation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.1-10
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• 2009

Inventory Management has become a very important issue in supply chain management, because inventories may be used as a means to accomplish the certain strategic goals in company decisions. RFID(radio frequency identification) technology is used to help manage inventories. It is known that the ideal control of inventories is to replenish item by item. This paper points out several misinterpretations from the Wal-mart report presented in '07 Seoul Forum and suggests the new direction of RFID application. In this paper we consider RFID as not 'identification technology' but 'information technology.' The 'RF-Kanban' suggested here is adopted from the'Kanban'concept of TPS(Toyota Production System). The RF-Kanban system shows the easier control for replenishing various items in boxes. Lots of inventories can be reduced through RF-Kanban System. This work develops the protocol of RF-Kanban and introduces the case study for easier understanding.