• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.4
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• pp.143-153
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• 2001

In this study we develop a computer simulation model to evaluate the effects of various production and order processing policies measured in terms of on-time delivery rate and average waiting time of job orders. Policies considered include : eliminating inflated due date, lot splitting, loss time reduction, attaining full flexibility in production lines, and selective order promising scheme. Actual order-production data from a chemical company were used in the simulation model. Based on the simulation results, we make several suggestions that can significantly reduce the production lead time and increase the on-time delivery rate.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.1
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• pp.29-44
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• 2013

This study suggests that as receiving feedback is moved back, the effectiveness of problem-solving increases. Utilizing data from innovation contests in which a number of problem solvers compete with each other, we answer questions such as whether the order of receiving first feedback affects problem-solving effectiveness and how problem-solving experience moderates the relationship between the first feedback order and problem-solving effectiveness. Empirical results based on data collected from Kaggle, an online platform for innovation contests, showed that the order that contest participants receive the first feedback increases problem-solving effectiveness. Furthermore, the more prior experience of contest participants accentuates the suggested relationship between the order of receiving the first feedback and problem-solving effectiveness.

• Korean Management Science Review
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• v.29 no.3
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• pp.157-168
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• 2012

In this study, we consider an order promising problem at parallel machine shops where orders arrive dynamically. We develop methods for the problem, which instantly quote the due-dates of arrived orders. In this study, we first propose methods which can estimate flow times of orders, in which the current and future inventory status as well as the specific scheduling scheme used in the shop are taken into account, and then the due-dates are set by the order promising methods using the estimation results. The quoted due-dates of orders are compared with the actual completion times of those which are obtained from the simulation runs. The series of computational experiments show that the superior performance of the proposed methods in terms of the accuracy of due-date quotation.

• Management Science and Financial Engineering
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• v.17 no.1
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• pp.95-116
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• 2011

This paper considers a flowshop scheduling problem where a customer orders multiple products (jobs) from a production facility. The objectives are to minimize makespan and to minimize the sum of order (batch) completion times. The order cannot be shipped unless all the products in the order are manufactured. This problem was motivated by numerous real world problems encountered by a variety of manufacturers. For the makespan objective, we develop an optimal solution procedure which runs in polynomial time. For the sum of order completion time objective, we establish the complexity of the problem including several special cases. Then, we introduce a simple heuristic and find an asymptotically tight worst case bound on relative error. Finally, we conclude the paper with some implications.

• Korean Management Science Review
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• v.21 no.3
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• pp.101-113
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• 2004

In the rapidly propagating Internet based electronic transaction environment. the importance of real time order confirmation has been more emphasized, In this paper, using data mining techniques, we develop intelligent operations decision model to allow real time order confirmation at the time the customer places an order with required delivery terms. Among various operation plannings used for order fulfillment. mill routing is the first interface decision point to link the order receiving at the marketing with the production planning for order fulfillment. Though linear programming based mathematical optimization techniques are mostly used for mill routing problems, some early orders should wait until sufficient orders are gathered for optimization. And that could effect longer order fulfillment lead-time, and prevent instant order confirmation of delivery terms. To cope with this problem, we provide the intelligent decision model to allow instant order based mill routing decisions. Data mining techniques of decision trees and neural networks. which are more popular in marketing and financial applications, are used to develop the model. Through diverse computational trials with the industrial data from the steel company. we have reported that the performance of the proposed approach is effective compared to the present heuristic only mill routing results. Various issues of data mining techniques application to the mill routing problems having linear programming characteristics are also discussed.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.185-193
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• 2008

As buildings become higher and larger, the possibility of accident also increases, and recurrent accidents and serious accidents are also increasing. However, it is not possible to control all the hazardous activities in construction site. Therefore, hazardous activities with higher possibility should be identified and prioritized in advance so engineers and managers can control the activities in safe manner. For this purpose, this research adopts FMEA technique, which has been widely utilized in manufacturing industry. In order to apply FMEA technique in construction safety management, the process of construction work is divided into sub-processes or activities. Then FMEA technique is applied to quantitatively analyze the importance of each activity from the safety perspective.

• Management Science and Financial Engineering
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• v.15 no.1
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• pp.1-31
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• 2009

This paper considers the value of warehousing contract under probabilistic demands. We consider a supply chain consisting of a supplier, a retailer and its third-party warehousing partner who provides the warehousing service to the retailer through an outsourcing contract. A typical contract is specified by initial space commitment and modification schedule. The retailer decides the order quantity for the supplier and space commitment for the outsourcing contract. Since there is close relationship between order quantity and space commitment to minimize the total cost including ordering cost, inventory carrying cost, shortage cost, and warehousing cost, we develop an analytical model under probabilistic demands, where the retailer can determine the optimal order size and space commitment level jointly. We found the closed-form optimum for a single-period case and the optimal conditions for a two-period case. To evaluate the value of contract flexibility for the two-period case, we compared the total cost under two policies; one with modification, under which the base commitment can be changed at the start of each period and the other without modification. From results of our numerical analysis, we showed that the modification policy is more cost-effective as the variability of demand increases.

• Journal of Korea Society of Digital Industry and Information Management
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• v.20 no.2
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• pp.109-123
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• 2024

The purpose of this study is to identify strategic insights for cyber universities to secure a competitive advantage based on market analysis grounded in customer needs and motivations. As a research method, we surveyed and analyzed college students using conjoint analysis, identified the importance of cyber university components, estimated the utility of each detailed level, and identified the configuration of cyber universities most preferred by potential customers. In the study results, the importance of attributes that appeared by analyzing all respondents was in the order of 'expected ourcoms after graduation', 'department characteristic', 'cyber university name', and 'learning management style'. Cluster analysis was performed, divided into two groups, and conjoint analysis was performed. For Cluster 1, the importance values of the components were 'expected outcomes after graduation,' 'learning management style,' 'cyber university name,' and 'department characteristics,' in that order. For Cluster 2, the importance values were 'expected outcomes after graduation,' 'department characteristics,' 'cyber university name,' and 'learning management style,' in that order. As an application of the research, As an application of the study, it is suggested that analyzing the preferences of potential customers in the entire group is not accurate; therefore, segmenting the groups for analysis and strategy formulation can be useful.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.187-203
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• 2014

Objectives: As the demand to deal with pathogens in domestic research institutions has expanded and biological accidents have increased, the need for systematic biosafety management in infectious disease laboratories has grown. According to international standards, risk assessment (RA) is required for biosafety management. However, RA criteria have not been clearly established in Korea, so to this end I have attempted to determine RA criteria meeting international levels Methods: In order to provide RA criteria for application, I analyzed the RA criteria in use in the U.S., Europe and at international organizations. In order to ensure the public nature of the RA criteria, I constructed the research model through modified management consulting methodology reflecting the model of Radnor and O'Mahoney. Results: According to the results of the study, existing laboratory biosafety regulations were comparable to domestic laboratory safety laws. Existing laboratory biosafety standards that are designed around risk factors were found to be insufficient. An RA case to be carried out in infectious disease laboratories at the National Institute of Health of KCDC was identified. Conclusion: To establish a systematic risk management system meeting international standards, it was necessary first to harmonize the systems of national and international standards. In addition, in order to provide specific biosafety management on-site, I recognized a need for methodology and planning strategies to discover biosafety management so that it can be carried out as required through the RA of individual laboratories.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.4
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• pp.121-133
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• 2008

In manufacturing companies, engineering information is a central data which defines a product to be produced. This is changed by various factors such as changes of product configuration, changes of drawings information of a technology's licensor, etc, and these changes essentially accompany the changes of a product BOM (Bill of Materials) structure. Thus, engineering changes gives a heavy burden to information management within enterprise because the changes of product BOM have an influence on each departmental BOM such as a procurement BOM, a manufacturing BOM, a quotation BOM, etc. Especially, these changes of product BOM due to the engineering changes is inevitably and frequently happened by a customer's requirements in a customer-oriented make-to-order manufacturing environments. In these manufacturing environments, information gap among each department from the first contact point of customer to engineering, materials, production, quality, and management is very close, and thus it is very important that the change information of product BOM due to changes of product specification and engineering information are efficiently communicated among each department. This paper describes a procedure of determining product specification and of generating product BOM, and proposes an efficient management scheme for the change process of product BOM information due to changes of product specification and engineering. Also, to show the effectiveness of the proposed product BOM management scheme, a product BOM management system is implemented for the ship engine division of 'H' company, one of customer-oriented make-to-order manufacturing enterprises.