• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.155-166
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• 2007

The purpose of this research is to develop a conceptual model and prototype that establishes a new approach for building cost estimating in the schematic design phage. This research use the method that analyzes quantity and unit price separately to enhance schematic cost estimating through conducting literature review andi analyzing existing schematic cost estimating methods. In addition, this study proposes tile concept of cost breakdown structure including two more classifications: building element and floor compared to existing one only classified by trade. Thus, a Quantity Based Active Schematic cost Estimating(Q-BASE) model is developed founded on those two concepts. By applying proposed schematic cost estimating model, historical structure cost of residential complex building project is analyzed, and then, based on this analysis, prototype is implemented.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.168-175
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• 2011

Construction accidents are major problem in Turkish Construction industry and especially fatally rates are very high. Current legislative system on occupational safety in Turkey enforces employers to implement safety measures as well as safety management systems. However level of consciousness in the industry is unsatisfactory and safety are perceived as extra cost and unnecessary expenditure. Moreover, especially in small residential building constructions which have a big share in the industry and unfortunately safety measures to mitigate or abate construction risks do not exist. The study focuses on small residential building construction sites and in the scope of this study, thirty building projects are examined. For each building project, project cost including labour and material costs, service and consultancy costs for mechanical, electrical systems as well as architectural and structural services, costs for supervision and finally general expenditures for construction site facilities were calculated. On the other hand, occupational safety costs for personal protective equipment, collective protective measures, consultancy and training were determined. Work breakdown structures were established and for each work item firstly occupational risks were evaluated and furthermore according to risk scores safety measures to be implemented were defined and related costs were calculated. The study gave results for total safety cost on average, in terms of percentage of total project cost (3.73% of total project cost), safety cost per man-hour (0.40 USD) and safety cost in terms of unit construction area (11.60 USD per square meter). Since safety management is a part of whole project management process, study gives suggestions and techniques to calculate safety costs and implement safety measures as a part of project management service for professionals. Authors believe that suggested approach may easily developed by the usage of more data to establish a model for estimation not only for building construction sites but also for all construction projects.

• Journal of the Korea Institute of Building Construction
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• v.10 no.6
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• pp.49-60
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• 2010

Cost Estimating allows each entity in a construction project to plan, distribute, and control its required construction cost for the project. However, existing 2D design based estimating has problems, such as inaccuracy and inefficiency caused by missing, duplicated, or erroneous calculations. In this situation, current estimations for school facilities have more difficulties in forecasting construction costs due to an inadequate work breakdown structure for BOQ (Bill of Quantity) and insufficient guidelines for Basis of Estimate. In this study, therefore, an effort was made to increase the efficiency of estimating for school facilities by applying a 3D modeling based BIM tool to quantity and cost estimates. In addition, this study suggested a reasonable work breakdown structure for BOQ that was appropriate when 3D modeling was applied, and verified it through a case study. The authors tried to provide a BIM-based estimating method for school facilities to obtain greater accuracy and efficiency by having more information in an earlier stage.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.655-662
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• 2010

As the national competitive power indicator, the infrastructures have been constructed with government's SOC budgets. However, even SOC budget is decreased, Public-Private Partnership Project (PPP project) has been introduced to solve demands on extending infrastructures, and among PPP projects, road projects take high portions. This study analyzes the operation & management item of financial model which is connected to the O&M cost and project proposal of previously proposed road project and analyzes the Korea Expressway Co.,'s project cost items and O&M tasks to reflect the characteristics of road projects. Based on results, this study suggests necessity of the O&M cost breakdown structure and the cost calculation standard on each cost item. Also, for the existing task execution tools, O&M cost calculation tool and finance analysis task tool will be integrated, and the system is suggested web-based system. Thus, it is expected that it contributes to the securing overall business values on PPP project and expending profit-base infrastructures.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.196-197
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• 2014

Low carbon construction is an important operation management goal such as cost, time, and quality in construction community. This paper introduces a system which measures the variability of carbon dioxide amounts. First, this system allows creating construction operation models of which the level of detail is breakdown into the work task level. Second, the system implements sensitivity analysis along with a ranges of resources that are allocated in an operation model. It facilitates to find the optimal resource combination using the operation performances such as the amount of emissions, operation completion time, and cost. Lastly, it identifies the best fit probability distribution functions of performance criteria given a certain resource combination. It allows project manager to query the percentages to complete the operation within a limitation specified by the system users.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.67-68
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• 2016

In construction management, BoQ(Bill of Quantities) has been commonly used for the cost estimation. However, many problems have been recognized about the work items used in the BoQ that could be varied by the experience and knowledge of the estimators or the project. Also, there are lots of work items that have to be written in BoQ even though the cost proportion of those items is relatively lower than the others. In this study we consider the way how to organize optimally the work items through the analysis of case. The results of this study could be useful for improving the efficiency of preparing construction BoQ and conducting Quantity take-off in our construction management practices.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.561-566
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• 2006

In this paper, we propose a new ship scheduling set packing model considering limited risk or variance. The set packing model is used in many applications, such as vehicle routing, crew scheduling, ship scheduling, cutting stock and so on. As long as the ship scheduling is concerned, there exits many unknown external factors such as machine breakdown, climate change and transportation cost fluctuation. However, existing ship scheduling models have not considered those factors apparently. We use a quadratic set packing model to limit the variance of expected cost of ship scheduling problems under stochastic spot rates. Set problems are NP-complete, and additional quadratic constraint makes the problems much harder. We implement Kelley's cutting plane method to replace the hard quadratic constraint by many linear constrains and use branch-and-bound algorithm to get the optimal integral solution. Some meaningful computational results and comments are provided.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.293-299
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• 1996

The breakdown of machines lead to the lateness of parts and the change of schedules. Its treatment is very important problem in the shop floor control system. In this study, we present an algorithm minimize the lateness, earliness and change of schedule by controlling machining speed of available machines. Production time and production cost required to manufacture a piece of product are usually expressed as a unimodal convex fuction with respect to machining speed, and each has its minimal point at the minimum time speed or the minimum cost speed, and a speed range between these two speeds is called 'efficiency speed range'. Therefore, the algorithm determines the machining speed in the efficiency speed range. An example is demonstrated to explain the algorithm.

• Korean Journal of Construction Engineering and Management
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• v.10 no.1
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• pp.26-35
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• 2009

Work breakdown structure (WBS) can be used as an information center in earned value management system (EVMS) for the construction project. Because EVMS results, such as schedule variance and cost variance, are analyzed for the selected WBS code, the role of WBS code is important in EVMS. This study suggests a methodology for organizing WBS map with a quadrant. It can represent the project organization collectively by work level in a coordinate system. And the study developed an EVMS tool based on the WBS map and this tool can visualize various attribute indexes of EVMS by color symbols. Those methodologies can be used for improving practical application of EVMS.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.17-24
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• 2013

In order to have market competitiveness in local and global areas, Domestic Marine Leisure Industry business, which is a latecomer in the Marine Leisure industry, should retain a strong market adaptability by reducing time and cost that are required for work of planning, designing, and preparation for product development. To meet above requirements, it is essential that integrated system control extensive marine leisure industry. After ensuring integrated information by figuring out the systematic link between related-industries, the core of this research is to secure information classifications that are not just in the flow of simple serial order, but in that of integration and object-oriented information classifications. For this end, we examine other similar cases in industries using real information system applied to industrial production and Product Lifecycle Management (PLM), Product Data Management (PDM), Digital Manufacturing (DM) and applying the same methodology to review practical application in order to construct the information system, and Work Breakdown Structure (WBS), compared with the case studies. Through this basic task for the marine leisure industry classification system configuration (Work Breakdown Structure, WBS) and utilizing information of driving real companies of marine leisure industry, a unique area of MLWBS (Marine Leisure Work Breakdown Structure, MLWBS) is configured. This Marine Leisure Work Breakdown Structure can be used in various areas of applications like products, design information, engineering, production, purchasing, sales, marketing, AS, utilizing various forms of customer support.