• Journal of the Korea Society for Simulation
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• v.15 no.3
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• pp.39-47
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• 2006

In most of supply chain planning practices, the estimated demands, which are forecasted for each individual period in a forecasting window, are regarded as deterministic. But, in reality, the forecasted demands for the periods of a given horizon are stochastically distributed. Instead of using a safety stock, this study considers a direct control of service level by choosing the demand used in planning from the distributed forecasted demand values for the corresponding period. Using the demand quantile and echelon stock concept, we propose a simple but efficient heuristic algorithm for multi-echelon serial systems under service level constraints. Through a comprehensive simulation study, the proposed algorithm was shown to be very accurate compared with the optimal solutions.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.745-747
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• 2005

After restructuring electricity industry, national long term electricity plans moved to "Basic plan of electricity supply and demand" from "Long term power development plan". The main point is a change of path from plan of power development at national level to plan of electricity supply and demand at company level. A proposal by generation company is surveyed and reflected to the basic plan of electricity supply and demand. The second plan shows over 40% reserves in result of the proposals. It is the time to evaluating the proposal which covers market function in the basic plan of electricity supply and demand at the stage of market change. This research presents the need of evaluation of proposals and the methods of evaluation. Also it presents the alternative planning procedure to reflecting the evaluation methods.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.57-69
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• 2021

Urban green spaces supply ecosystem services (ESs), which are consumed by city residents and generate demand, to improve air quality. It is important to determine supply and demand for ESs and reduce the gap for efficient management. This study proposed a method to use the concept of supply and demand for ESs in the decision-making process for urban planning or management. PM₁₀ concentrations were converted to weight for demand assessment on PM₁₀ reduction, and PM₁₀ absorption capacity of all green spaces including the forests, and that of urban green spaces excluding forests, was calculated for each supply assessment. The differences in the calculated supply and demand were analyzed to derive the mismatched regions in Suwon. As a result, regions with big forested areas showed sufficient supply, indicating that the degree of mismatch among administrative neighborhoods (dong) varied greatly depending on whether they had a forest. An analysis of only urban green spaces showed that all neighborhoods lacked supply. Forests with high PM₁₀ absorption capacity had a great effect, but urban green spaces can be considered a key element in reducing PM₁₀ in daily life. Considering the mismatch of supply and demand, spatial distribution, and population distribution, it is possible to prioritize the supply of urban green spaces to reduce PM₁₀ and, furthermore, support decision making for priority zones subject to forest conservation and designation and cancellation of green spaces, which gives significance to this study.

• Health Policy and Management
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• v.9 no.3
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• pp.33-52
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• 1999

The purpose of this study is to project the supply and demand for nurses till the year 2012 and to make recommendations for establishment of proper policies regarding them. To predict the supply of nurses. a baseline projection and demographic methods were employed. The derivative demand was used to forecast the demand of nurses. The results of this study provide us with valuable information on nursing manpower planning for the 21th century. Specifically. results indicate that there will be an oversupply of nurses in the near future based on the current productivity. Based on the medical law. there will be an undersupply of nurses till 2002 but an oversupply after that. Thus. the active supply of nurses must be decreased. One way to achieve this would be decreasing the size of training and education. Thus. we recommend that the number of entrances to 4 year programs will be reduced 20% in 2004. and a reduction of 20% by 2005 in 3 year programs. The results of this study suggest the following: First. a manpower bank for nurses who are trying to reenter the market must be established. Second, improvement of education and retraining is needed for the quality control of nurses. Further studies should take into consideration the above factors.

• Journal of the Korea Society for Simulation
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• v.12 no.1
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• pp.35-48
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• 2003

This paper suggests the long-term strategy of the production distribution planning considering the capacity of factory production and the uncertain demand in a supply chain. This paper determines the near optimal capacity of factory production by using the advantages of mathematical and simulation models. Also, the relationship between the capacity from the suggested model and the strategy of production and distribution in a supply chain is studied. Arena is used for modeling and analysis.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.1-13
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• 2009

This paper presents a coordinated planning model of price-dependent demand for a single-manufacturer and a single-retailer. The demand is assumed to be normally distributed, with its mean being price dependent. The manufacturer and retailer coordinate with each other to jointly and simultaneously determine the retail selling price and the retailer order quantity to maximize the joint expected total profit. This model is then compared to a 'returns' policy model where manufacturer buys back unsold items from the retailers. It is shown that the optimal total profit is higher for coordinated planning model than that for the returns policy model, in which the retail price is set by the retailer. A compensation or profit sharing scheme is then suggested and it is shown that the coordinated model with profit sharing yields a 'win-win' situation. Numerical results are presented to illustrate the profit patterns for both linear and nonlinear demand functions. The coordinated planning model, in addition, has a lower optimal price than for a returns policy model, which would result in higher sales, thus expanding the markets for the whole supply chain.

• IE interfaces
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• v.17 no.spc
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• pp.79-89
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• 2004

Supply Chain (SC) can balance demands with supply activities as executing Supply Chain Planning (SCP). The fluctuated demands, however, will break the balance between demand and supply. It means that the present SCP is useless in responding the changed demands. Thus it is necessary for SCP to be updated with changed demands. We call this procedure as Supply Chain Replanning. However, the existing measures for SC can not deal with the balance between supply and demand so that they can not detect effectively the timing of replanning. For this reason, a new performance measure, Balancing Point, is developed using momentum, a concept of Physics. It can treat the balance between supply and demand. Also, a replanning method based on Balancing Point is proposed. The proposed method is more effective than the existing replanning method, periodic replanning method and net inventory method.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.39-44
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• 2012

Water supply capacity and operational capability in agricultural reservoirs are expressed differently in the limited storage due to seasonal and local variation of precipitation. Since agricultural water supply and demand basically assumes the uncertainty of hydrological phenomena, it is necessary to improve probabilistic approach for potential risk assessment of water supply capacity in reservoir for enhanced operational storage management. Here, it was introduced the irrigation vulnerability characteristic curves to represent the water supply capacity corresponding to probability distribution of the water demand from the paddy field and water supply in agricultural reservoir. Irrigation vulnerability probability was formulated using reliability analysis method based on water supply and demand probability distribution. The lower duration of irrigation vulnerability probability defined as the time period requiring intensive water management, and it will be considered to assessment tools as a risk mitigated water supply planning in decision making with a limited reservoir storage.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.135-146
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• 2004

This paper first addresses a distribution planning method on centrally controlled supply chain. The distribution channels are assumed to be network of arborescence form. For such distribution networks, this study proposes a distribution planning scheme when the demands for retail sites are provided for a given planning horizon. As the planning horizon rolls forward, for a new horizon, forecasted demand distributions of periods in the horizon are updated. An idea of controlling customer service level by the selection of demand to be used in the planning (Demand Used in Planning, DUP) from the forecasted values is also discussed.

• Korean Management Science Review
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• v.19 no.2
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• pp.75-89
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• 2002

According to the fast-paced environment of information technology and improving customer services, the design activities of logistics systems improve customer centric services and delivery performance implementing e-logistics system. The fundamental design issues that arise in the delivery system planning are optimizing the system with minimum cost and maximum throughput and service level. This study is concerned with the integrated model development of delivery system with customer responsive service level for DCM, Demand Chain Management. We used a two-step approach for this study. First, we formulated the supply. center facility planning using stochastic set-covering problem and assigned the customers to the supply center using clustering algorithm. Second, we developed vehicle delivery planning for a supply center based on GIS, GIS-VRP. Also we developed a GUI-type computer program for proposed method for supply center problem using GIS and Geo-DataBase of Busan area. The computational results showed that the proposed method was very effective on a set of test problems.