• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.137-158
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• 1992

We study the Multiple Product Single Facility Stockout Avoidance Problem (SAP). That is the problem of determining, given initial inventories, whether there is a multiple product single facility production schedule that avoids stockouts over a given time horizon. The optimization version of the SAP where stockouts are pnelized linearly is also studied. We call this problem the Weighted Stockout Problem (WSP). Both problems are NP-hard in the strong sense. We develop Mixed Integer Linear Programming (MIP) formulations for both the SAP and the WSP. In addition, several heuristic algorithms are presented and performances are tested using computational experiments. We show that there exist polynomial algorithms for some special cases of the SAP and the WSP. We also present a method to phase into a target cyclic schedule for infinite horizon problems. These can be used as a practical scheduling tool for temporarily overloaded facilities or to reschedule production after a disruption.

• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.131-140
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• 2020

In this study, we analyzed the effect of consumer's cognitive response, emotional response and behavioral response on online shopping stockouts (ISRI: Individual Stockout Response Index). And we try to show the heterogeneity of the degree of consumer response by subdivision market based on the regularity of distribution. The ISRI was developed by Kim and Lee in 2016 and 2018, which were based on the items and factors of cognitive, emotional and behavioral responses. The exponential stockouts response of consumers in this study will give an accurate picture of what consumers want when stockouts. further research should be done on how consumers' reactions are influenced by situational characteristics, consumer characteristics, store characteristics and brand / product characteristics. Especially, the price level of the product will affect the consumer 's response in the case of online fashion goods shopping.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.426-426
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• 1999

;There are many sources of uncertainty in a typical production and inventory system. There is uncertainty as to how many items customers will demand during the next day, week, month, or year. There is uncertainty about delivery times of the product. Uncertainty exacts a toll from management in a variety of ways. A spurt in a demand or a delay in production may lead to stockouts, with the potential for lost revenue and customer dissatisfaction. Firms typically hold inventory to provide protection against uncertainty. A cushion of inventory on hand allows management to face unexpected demands or delays in delivery with a reduced chance of incurring a stockout. The proposed strategies are used for the design of a probabilistic inventory system. In the traditional approach to the design of an inventory system, the goal is to find the best setting of various inventory control policy parameters such as the re-order level, review period, order quantity, etc. which would minimize the total inventory cost. The goals of the analysis need to be defined, so that robustness becomes an important design criterion. Moreover, one has to conceptualize and identify appropriate noise variables. There are two main goals for the inventory policy design. One is to minimize the average inventory cost and the stockouts. The other is to the variability for the average inventory cost and the stockouts The total average inventory cost is the sum of three components: the ordering cost, the holding cost, and the shortage costs. The shortage costs include the cost of the lost sales, cost of loss of goodwill, cost of customer dissatisfaction, etc. The noise factors for this design problem are identified to be: the mean demand rate and the mean lead time. Both the demand and the lead time are assumed to be normal random variables. Thus robustness for this inventory system is interpreted as insensitivity of the average inventory cost and the stockout to uncontrollable fluctuations in the mean demand rate and mean lead time. To make this inventory system for robustness, the concept of utility theory will be used. Utility theory is an analytical method for making a decision concerning an action to take, given a set of multiple criteria upon which the decision is to be based. Utility theory is appropriate for design having different scale such as demand rate and lead time since utility theory represents different scale across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. Using utility theory, three design strategies, such as distance strategy, response strategy, and priority-based strategy. for the robust inventory system will be developed.loped.

• Fashion & Textile Research Journal
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• v.17 no.5
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• pp.770-780
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• 2015

This study intended to explore fundamental causes affecting consumers' response actions from psychological factors in the situation of sellout occurring during shopping in online fashion stores. In addition, this study devised a virtual online shop in order to measure consumers' cognitive and emotional psychological responses they experienced when goods were sold out. The subjects involved women in 20s~30s, major customers of online shopping, and the subjects were randomly allocated to one of eight questionnaire forms (2(stockout size: high vs low)${\times}2$(product assortment similarity: similar vs. dissimilar)${\times}2$(restocking cue: included vs excluded)). The number of final data used for the analysis was 336 and through SPSS 21.0 program, two-way ANOVA and bootstrap were utilized. The analysis result was that consumers' psychological responses (emotions, psychological reactance) of online shops differed by means of varying stockout situations. The stockout size had positive effect on psychological reactance and negative emotions. On the other hand, there was no difference in positive emotions (arousal) according to stockout size. In stockout situation of online fashion store, the moderating effect of product assortment similarity and restocking cues were verified. According to the analysis result, interaction effects between stockout size and restocking cues, product stockout size and product assortment for psychological reactance were significant. Lastly, the mediation effect of psychological reactance and emotion between stockout size and behavioral response was tested. As a result, the moderated mediation effects of psychological reactance for substitute were significant when product assortment was dissimilar and restocking cue was exclude.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.110-118
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• 2020

It is important to have an appropriate amount of inventory for effective operations. This study seeks to develop a sustainable newsvendor model by incorporating environment-related costs into the existing well-known (single-period) newsvendor model. Since leftovers do more harm to environments than stockouts, the optimal order amount tends to be lower than the traditional quantity. However, this is not the case when a second buy is allowed. A second order opportunity is prevalent in industries where it improves demand forecast despite incurring extra costs. In this study, we conduct an extensive numerical analysis for a newsvendor situation with a permitted second buy. The results show that we can reduce inventory costs by considering sustainability concerns. The research idea of including sustainability considerations into existing inventory models can be extended to a more general case and provides managerial insights for better inventory decisions.

• Journal of Distribution Research
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• v.16 no.4
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• pp.29-64
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• 2011

Overview of Research: Product availability is one of important competences of store to fulfill consumer needs. If stock-outs which means a product what consumer wants to buy is not available occurs, consumer will face decision-making uncertainty that leads to consumer's negative responses such as consumer dissatisfaction on store. Stockouts was much studied in the field of academia as well as practice in other countries. However, stock-outs has not been researched at all in Marketing and/or Distribution area in Korea. The main objectives of this study are to find out determinants of consumer responses such as Substitute, Delay, and Leave(SDL) when consumer encounters out-of-stock situation and then to examine the effects of these factors on consumer responses. Specifically, this study focuses on situational characteristics(e.g., purchase urgency and surprise), store characteristics (e.g., product assortment and store convenience), and consumer characteristics (e.g., brand loyalty and store loyalty). Then, this study empirically investigates relationships these factors with consumers behaviors such as product substitution, purchase delay, and store switching.