• 산업경영시스템학회지
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• 제39권1호
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• pp.17-24
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• 2016

Many organizations have transformed their business in order to survive and compete in the future. They generate projects by creating a vision, using strategies and objectives with funds aligning strategies and make efforts to complete them successfully because project success leads to business success. All projects have triple constraints such as scope, time, and cost to be completed. Project cost performance is a key factor to achieve project goals and which is mostly related with risks among various cost drivers. Projects require a cost estimation method to complete them within their budget and on time. An accurate budget cannot be estimated due to the uncertainties and risks. Thus some additional money should be funded in addition to the base budget as a contingency reserve for identified risks and a management reserve for unidentified risks. While research on contingency reserve for identified risks included in project budget baseline have been presented, research on management reserve for unidentified risks included in total project budget is still scarce. The lack of research on estimation method and role of the management reserve have made project managers little confidence to estimate project budget accurately with reasonable basis. This study proposes a practical model to estimate budgets including contingency and management reserves for not only project cost management but also to keep the balance of organization's total funds to maximize return on investments for project portfolio management. The advantages of the proposed model are demonstrated by its application to construction projects in Korea and the processes to apply this model for verification are also provided.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.274-277
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• 2006

건설 사업은 다양한 불확실성 및 리스크 요인으로 인하여 사업 수행 과정이 초기 계획대로 수행되고 있는지에 대한 반복적인 성과측정 및 후속 관리 조치가 필요하다. 이러한 성과 측정의 가장 대표적인 기준이 공정, 공사비, 품질이며 특히, 공정과 공사비의 경우 정량적인 평가가 가능하고 통합관리를 통해 효율성을 높일 수 있는 주요 관리 대상이 된다. 이를 위해 EVM(Earned Value Management)기법을 운영하도록 제도화 하였으며 EVM을 활용함으로써 사업 진도율 $15{\sim}30%$ 시점에서 사업의 EAC(Estimate at Completion)와 공정결과를 예측할 수 있다. 본 연구에서는 기존 EAC 추정의 문제점을 제시하고 회귀분석을 이용하여 적정 EAC 변동 범위를 예측한다. 따라서 공동주택 건설사업에서의 공사 수행 중 공정과 공사비의 문제점을 사전에 파악하여 변동 범위의 결과 값을 통해 의사결정자들이 효율적인 의사결정을 할 수 있도록 정보를 제공한 수 있을 것으로 판단된다.

• Industrial Engineering and Management Systems
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• 제11권4호
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• pp.397-405
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• 2012

This research proposes a framework of buffer management for multi-project systems in the critical chain project management (CCPM) method, expressed in the form of max-plus linear (MPL) representation. Since time buffers are inserted in the projects for absorbing uncertainties in task durations and protecting the completion times, the proposed method provides a procedure for frequently surveying the rates of consumed buffers and the rate of elapsed times. Their relation expresses the performance of the projects which is plotted on a chart through the completed processes. The chart presents the current performance of the projects and their interaction, which alerts managers to make necessary decisions at the right time for managing each project and the entire multi-project system. The proposed framework can analyze the complex system readily, and it enables managers to make an effective decision on scheduling. The effectiveness of the framework is demonstrated through a numerical example.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.393-399
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• 2009

This paper introduces an automated tool named Advanced Stochastic Schedule Simulation System (AS4). The system automatically integrates CPM schedule data exported from Primavera Project Planner (P3) and historical activity duration data obtained from a project data warehouse, computes the best fit probability distribution functions (PDFs) of historical activity durations, assigns the PDFs identified to respective activities, computes the optimum number of simulation runs, simulates the schedule network for the optimum number of simulation runs, and estimates the best fit PDF of project completion times (PCTs). AS4 improves the reliability of simulation-based scheduling by effectively dealing with the uncertainties of the activities' durations, increases the usability of the schedule data obtained from commercial CPM software, and effectively handles the variability of the PCTs by finding the best fit PDF of PCTs. It is designed as an easy-to-use computer tool programmed in MATLAB. AS4 encourages the use of simulation-based scheduling because it is simple to use, it simplifies the tedious and burdensome process involved in finding the PDFs of the many activities' durations and in assigning the PDFs to the many activities of a new network under modeling, and it does away with the normality assumptions used by most simulation-based scheduling systems in modeling PCTs.

• 대한산업공학회지
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• 제39권5호
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• pp.429-439
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• 2013

The Korean Veterans' Pension Fund has previously pre-purchased Gibril Tower on Business Complex in Dubai, UAE, via a project-financed construction investment. Although the property is near completion, the investor syndicate's attempt to debt-finance due arrears was foiled in Dubai central bank's credit control of real estaterelated loans. Accordingly, the investment coordinator offered an additional capital injection, a collateralized leverage, and a maturity extension to the syndicate. If the syndicate rejects the offer, they may risk a nearcomplete capital loss and a possible default of the main contractor. Otherwise, the syndicate may still face uncertainties regarding interest receivables, principal re-payment, foreclosure, economic recession in Dubai, and the Islamic bond bill in the Korean Parliament. A possible exercise of the latter option may be due to the agency-prone nature of pension fund managers. Given these qualitative risk factors as at April 1, 2011, a real options approach-implied optimal decision suggests an extended and complete cash augmentation into the project finance deal.

• 한국산학기술학회논문지
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• 제11권4호
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• pp.1442-1448
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• 2010

민간 주도형 사회간접자본(social overhead capital: SOC) 사업은 프로젝트의 규모와 장기에 걸친 공사의 불확실성 때문에 프로젝트의 경제성 분석을 하는 것은 복잡하다. 일반적으로 사용하고 있는 현금흐름 할인모형(discount cash flow model; DCF)은 미래의 불확실성 변수들을 적절히 반영하지 못한다는 한계점을 가지고 있지만 현실적으로 많이 쓰이고 있는 방식이다. 본 논문은 옵션기반모형에 근거한, BOT-옵션가치평가(BOT-OV)모형을 국내 민간 SOC 사업의 경제성 분석을 위해 적용한다. BOT-OV모형을 적용하는 것이 기존 순현재가치(net present value; NPV)방식을 통하여 프로젝트 가치 평가 할 때보다 더 정밀한 경제적 타당성 평가를 할 수 있다는 것을 확인하여 기존의 NPV 평가방식의 방법을 대체할 수 있는 가능성을 확인하는데 의의가 있다고 할 수 있다.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1208-1211
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• 2005

The design phase has a great influence on the success of subsequent phases in the project which can be connected with the success of the overall project. Several studies have focused on the effective design management. However, it is too complicated and difficult to manage the design process for the reason that it has a lot of participants and design information and consists of thousands of decisions by an architect alone. Accordingly, it is the main issue for the success of the project how well the design phase be organized and managed. In recent, even in domestic, the importance of design phase has begun to be referred in the conferences. Lean Construction also has a close look at those issues and makes ready to apply specific management methods, called to Lean Design & Construction. Managers can consider a variety of uncertainties to be under control through making the overall process effectively from the early stage. By establishing the efficient process from the design phase before the construction phase, managers can result in a desirable productivity. The aim of this study is to bring the concept (Lean Design & Construction) in domestic design circumstances and verifies the possibility how to apply the concept to the design phase.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.496-500
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• 2015

International construction projects are inherently more risky than domestic projects with multi-dimensional uncertainties that require complementary risk management at both the country and project levels. However, despite a growing need for systematic country evaluations, most studies have focused on project-level decisions and lack country-based approaches for firms in the construction industry. Accordingly, this study suggests data-driven approaches for evaluating countries using two quantitative models. The first is a two-stage country segmentation model that not only screens negative countries based on country attractiveness (macro-segmentation) but also identifies promising countries based on the level of past project performance in a given country (micro-segmentation). The second is a multi-criteria country segmentation model that combines a firm's business objective with the country evaluation process based on Kraljic's matrix and fuzzy preference relations (FPR). These models utilize not only secondary data from internationally reputable institutions but also performance data on Korean firms from 1990 to 2014 to evaluate 29 countries. The proposed approaches enable firms to enhance their decision-making capacity for evaluating and selecting countries at the early stage of corporate strategy development.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.534-541
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• 2011

Risk evaluation approaches for bidding on international construction projects are typically partitioned into three stages: country selection, project classification, and bid-cost evaluation. However, previous studies are frequently under attack in that they have several crucial limitations: 1) a dearth of studies about country selection risk tailored for the overseas construction market at a corporate level; 2) no consideration of uncertainties for input variable per se; 3) less probabilistic approaches in estimating a range of cost variance; and 4) less inclusion of covariance impacts. This study thus suggests a three-staged risk evaluation model to resolve these inherent problems. In the first stage, a country portfolio model that maximizes the expected construction market growth rate and profit rate while decreasing market uncertainty is formulated using multi-objective genetic analysis. Following this, probabilistic approaches for screening bad projects are suggested through applying various data mining methods such as discriminant logistic regression, neural network, C5.0, and support vector machine. For the last stage, the cost overrun prediction model is simulated for determining a reasonable bid cost, while considering non-parametric distribution, effects of systematic risks, and the firm's specific capability accrued in a given country. Through the three consecutive models, this study verifies that international construction risk can be allocated, reduced, and projected to some degree, thereby contributing to sustaining stable profits and revenues in both the short-term and the long-term perspective.

• 한국건설관리학회논문집
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• 제10권4호
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• pp.14-25
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• 2009

공동주택 개발사업은 대규모의 자원과 인력이 투입되는 중장기 복합공정 사업으로 사업 내 외적 영향요인이 복합적으로 관계되는 바, 사업추진 시 현장여건을 비롯한 정치 경제 사회 분야의 내 외부 불확실성 요소로 인한 많은 사업 리스크가 발생하게 된다. 이러한 리스크는 사업의 성패를 결정짓는 중요한 인자로서 작용하게 되며, 종국에 기업의 수익 및 재무구조를 변화시키는 중점 관리요인으로 그 중요성이 크게 대두되고 있어 이에 따른 리스크 저감을 위한 방안 및 효율적인 대책이 필요하다. 이와 같은 관점에서 본 연구에서는 건설프로젝트 중 공동주택 개발사업을 대상으로, VE기반 리스크 관리모델 및 절차를 수립하고 이에 따른 사업 추진 시 기획 및 설계, 시공, 유지관리에 이르는 전 단계에서의 발생 가능한 리스크 요인을 총 3단계 10분류 81개 항목으로 도출, 분석하고, 각각의 리스크 항목별 중요도를 가치공학(VE)을 기반으로 하여 평가 제시함으로써 궁극적으로 개발사업의 성공적인 추진과 이에 따른 공공 및 민간 건설 산업의 경쟁력을 확보할 수 있는 기초자료를 제시하였다.