• Journal of the Korea Society for Simulation
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• v.23 no.3
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• pp.19-25
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• 2014

Demand forecasting is the basis of management activities including marketing strategy. Especially, the demand of a part is remarkably important in supply chain management (SCM). In the fields of various industries, the part demand usually has the intermittent characteristic. The intermittent characteristic implies a phenomenon that there frequently occurs zero demands. In the intermittent demands, non-zero demands have large variance and their appearances also have stochastic nature. Accordingly, in the intermittent demand forecasting, it is inappropriate to apply the traditional time series models and/or cause-effect methods such as linear regression; they cannot describe the behaviors of intermittent demand. Markov bootstrap method was developed to forecast the intermittent demand. It assumes that first-order autocorrelation and independence of lead time demands. To release the assumption of independent lead time demands, this paper proposes a modified bootstrap method. The method produces the pseudo data having the characteristics of historical data approximately. A numerical example for real data will be provided as a case study.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1207-1212
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• 2003

As development of the e-commerce, the distributing network for a logistics currency is more complicated. A management of the distributing network (DN) is important factor in distribution planning. The DN can be expressed to distribution center (DC) and the interaction of DC. An internal factor of DC and an external factor to occur by an interaction of DC have many influences on the DN. Therefore, for an efficient DN management plan, analysis of the DN that considered DC and an interaction of DC is required. Until now a study on a viewpoint of supply chain management as resources assignment was performed, but the study on analysis of the distribution network was not performed. This paper propose the distribution network analysis technique that considered DC and an interaction of DC. A proposed technique consists of two steps largely. First of all a DN is expressed with the graph that included an interaction of DC and DC. It uses a reachibility tree, and the following, a DN expressed with a graph is analyzed. Also we presented an example model, and show an usefulness of proposal technique with the analysis of this model.

• Korean Journal of Computational Design and Engineering
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• v.15 no.6
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• pp.425-439
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• 2010

The current challenge with which most shipyards are forced is to reduce the design time and the time-to-delivery because of explosive order of shipbuilding. Collaborative design and product data management have become important to reduce the lead time. Furthermore, enterprise information technologies such as ERP (Enterprise Resource Planning), SCM (Supply Chain management), and APS (Advanced Planning System) requires the collaborative environment. Also, manufacturing environment has been considered as a topic of strategic interest to get shorter product lifecycles in shipyards. Most shipyards have chosen an environment of ETO (Engineering To Order) strategy which designs and produces new products in response to various requirements of customer, rules and regulations. In the ATO (Assemble 10 Order) environment, most component parts have been designed to be procured or produced on the order requirement. The basic distinction between the ETO and ATO is the timing of the design. Thus in the ATO environment, it is more flexible in reducing the lead time to meet the specified requirements of customers. However, the ETO strategy requires new ship design process and ship product structures that are linked with the implementation of PLM. And, the function and architecture of current PLM solution has been designed based upon ATO environment properly. This paper presents the PLM architecture which effectively reflects the characteristics of shipbuilding. 4-layer architecture model is suggested to implement the PLM system. Also, implemented functions of ship PLM is explained in order to make a practical guidance for ship PLM implementation.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.405-430
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• 2021

Production planning is a key part of production management of manufacturing enterprises. Since computerization began, modern production planning has been developed starting with Material Requirement Planning (MRP), and today Enterprise Resource Planning (ERP), Advanced Planning and Scheduling (APS), Supply Chain Management (SCM) has been spreading and advanced. However, in the shipbuilding field, rather than applying these general-purpose production planning methodologies, in most cases, each shipyard has developed its own production planning system. This is because the applications of general-purpose production planning methods are limited due to the order-taking industry such as shipbuilding with highly complicated construction process consisting of millions of parts per ship. This study introduces the design and development of the production planning system reflecting the production environment of heavy shipyards in Korea. Since Korean shipyards such as Hyundai, Daewoo and Samsung build more than 10 ships per year (50-70 ships in the case of large shipyards), a planning system for the mixed production with complex construction processes is required. This study draws requirements using PI/BPR (process innovation and business process reengineering) methodology to develop a production planning system for shipyards that simultaneously build several ships. Then, CBD software development methodology was applied for the design and implementation of planning system with drawn requirements. It is expected that the systematic development procedure as well as the requirements and functional elements for the development of the shipyard production planning system introduced in this study will be able to present important guidelines in the related research field of shipbuilding management.

• Journal of Navigation and Port Research
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• v.34 no.2
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• pp.131-136
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• 2010

The aim of the paper is to solve the problem of customer reduction due to the difficulty of parts sourcing which impacts production delay and delivery delay in SC networks. Furthermore, this paper is to suggest the new inventory policy of MTS in order to solve the problem of current inventory policy. In order to compare two policies, a LCD maker is selected as a case study and the real data for 2007 years is used for simulation input. The maker uses MTO policy for parts sourcing which has the problem of lead time even if it has some advantage of inventory cost. Based on current process. The simulation program of AS-IS model and TO-BE model using ARENA 10 version is developed for evaluation. In a result, the order number of two policies shows that MTO is 52 and MTS is 53. However the quantity of order shows big difference such that MTO is 168,460 and MTS is 225,106. Particularly, the lead time of new inventory policy shows much shorter that that of MTO such that MTO 100 is days and MTS is 16 days. In spite of short lead time by MTS policy, new policy has to take burden of inventory cost per year. Total inventory cost per year by MTS policy is US$ 11,254 and each part inventory cost is that POL is US$ 1,807, LDI is US$ 2,166 and Panel is US$ 7,281. The implication of the research is that the company has to consider the cost and the service simultaneously in deciding the inventory policy. In the paper, even if the optimal point of deciding is put into tactical area, the ground of decision is suggested in order to improve the problem in SC networks.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.170-181
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• 2015

Generally, because individual agricultural product possesses its own distinctive characteristics and shows different characteristics at each stage of the agricultural supply chain, it is necessary to develop a proper enterprise architecture for managing information system. In this paper, we propose an enterprise architecture based on RFID/USN technology that can be used as a reference enterprise architecture for u-IT application in the agriculture sectors, which is called the u-Farm enterprise architecture with taking heterogeneous characteristics of agricultural products into account for. In addition, we also developed the RFID/USN middleware platform as a core infrastructure technology. Fo evaluation of the performance of the proposed u-Farm architecture and the RFID/USN middleware platform, the field-trial evaluation at the apple Agricultural Processing Center (APC) has been executed and the results shows that the proposed architecture and platform perform well in terms of information integration over the whole SCM process from the farming stage to delivering statge to the customers. It is expected that the proposed u-Farm enterprise architecture can be utilized as a standard information architecture, and the RFID/USN middleware platform can be a infrastructure platform for future u-IT based information technology applications and services in the agricultural environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.6
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• pp.57-68
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• 2004

Recently, Radio Frequency Identification (RFID) systems stands in the spotlight of industry as a common and useful tool in manufacturing, supply chain management (SCM) and stock management. In the near future, low-cost RFID Electronic Product Code; (EPC) or smart-labels may be a practical replacement for optical barcodes on consumer items. However, manufacturing cheap and small RFID tags, and developing secure RFID authentication Protocols are problems which need to be solved. In spite of advances in semiconductor technology, computation and storage ability of the tag are so limited that it is difficult and too expensive to apply existing crypto-systems to RFID tags. Thus it is necessary to create a new protocol which would require less storage space and lower computation costs and that is secure in the RFID system's environments. In this paper, we propose a RFID authentication protocol that is secure against location tracking and spoofing attacks. Our protocol can be used as a practical solution for privacy protection because it requires less computations in database than the previous RFID authentication protocol.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.93-103
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• 2021

S&OP(Sales and Operations Planning) is an ongoing process of periodic planning, reviewing, and evaluation through the involvement of all key stakeholders. Within this process, performance is regularly reviewed and early warning signals are generated, so that the company can react quickly to changing market and operational environment. This paper presents a framework for effective S&OP for fair alignment, accountability, teamwork, visibility, and risk management. This framework focuses on supply chain information governance, level of information sharing through S&OP, role of S&OP as coordination mechanism, APS effectivesness as a planning tool and SCM performance. In addition, a brief case study on the operating characteristics of S&OP at three Korean firms is presented. Implications of the study finding are also provided. It will also make companies that are considering the introduction of S&OP aware of the importance of S&OP, which will provide practical guidelines for the introduction of S&OP.

• International Commerce and Information Review
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• v.18 no.2
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• pp.131-150
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• 2016

As global partnership is recently getting important in order to establish supply chain network in global managing environment, companies tend to improve quality and warranty in SCM(Supply Chain Management) by certifying ISO(International Organization for Standardization). This research investigated structural relationship how strategic and operational ISO application level and trust, immersion, collaborative factors in partnership process affect to companies business performance. This research was surveyed with 147 manufacturing companies in South Korea and conducted empirical analysis using Structural equation model. The research hypothesis and model was derived from the basis of existing theory and empirical research, and obtained the following results. Firstly, the strategic ISO level showed positive(+) effect on trust and immersion factor. Second, the operational ISO level showed positive(+) effect on trust and collaborative factor. Third, trust factor in the partnership process showed positive(+) effect on immersion factor. Lastly, collaborative factor in partnership process showed positive(+) effect on companies business performance. Implication for this research is that companies must consider ISO application in establishing partnership and companies require prolonged effort using trust, immersing, collaborative factors into partnership process to improve business performance.

• Journal of Korea Port Economic Association
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• v.24 no.4
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• pp.329-347
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• 2008

This thesis aims to contribute to upgrading its position to the biggest 8 ports in Korea by suggesting activating schemes of Kunsan Port in rapidly changing shipping environments. The research methodologies such as literature survey, O/D analysis are adopted in the study. The following several conclusions can be suggested. Firstly, in port logistics system the dredging in navigational channels and in Kumgang Dam and the incentive schemes for the shipping companies and the international freight forwarders are required. Secondly cargo inducement schemes should be introduced to induce container cargoes originated in Junbook Do Province and adjacent area etc. Thirdly the development of new shipping routes and strengthening the coastal routes among domestic sea ports. Fouthly establishing supply chain management system with adjacent Chinese Provinces such as Shandong.