• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.327-330
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• 2007

This paper verifies that the normality assumption that the simulation output data, Project Completion Times (PCTs), follow normal distribution is not always acceptable and the existing belief may lead to misleading results. A risk quantification method, which measures the effect caused by the assumption, relative to the probability distribution of PCTs is implemented as an algorithm in MATLAB. To validate the reliability of the quantification, several series of simulation experiments have been carried out to analyze a set of simulation output data which are obtained from different type of Probability Distribution Function (PDF) assigned to activities'duration in a network. The method facilitates to find the effect of PDF type and its parameters. The procedure necessary for performing the risk quantification method is described in detail along with the findings. This paper contributes to improving the reliability of simulation based scheduling method, as well as increasing the accuracy of analysis results.

• International conference on construction engineering and project management
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• 2009.05a
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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.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.73-79
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• 2005

This paper, introduces a Stochastic Project Scheduling Simulation system (SPSS III) developed by the author to predict a project completion probability in a certain time. The system integrates deterministic CPM, probabilistic PERT, and stochastic Discrete Event Simulation (DES) scheduling methods into one system. It implements automated statistical analysis methods for computing the minimum number of simulation runs, the significance of the difference between independent simulations, and the confidence interval for the mean project duration as well as sensitivity analysis method in What-if analyzer component. The SPSS 111 gives the several benefits to researchers in that it (1) complements PERT and Monte Carlo simulation by using stochastic activity durations via a web based JAVA simulation over the Internet, (2) provides a way to model a project network having different probability distribution functions, (3) implements statistical analyses method which enable to produce a reliable prediction of the probability of completing a project in a specified time, and (4) allows researchers to compare the outcome of CPM, PERT and DES under different variability or skewness in the activity duration data.

• Journal of Software Assessment and Valuation
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• v.16 no.1
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• pp.21-26
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• 2020

The completeness appraisal of software is performed in various forms, such as assessing the completion level in the development process, calculating the defect rate, estimating the development cost, and calculating the redevelopment cost. Along with this, the problem that is often dealt with is estimation of the development time. Even in a dispute over completeness due to delays in software development, issues of calculating an appropriate development time required to develop a delivery software or a development time required for change requests are often included in the appraisal request. In this paper, we introduce the procedure and method for estimating the appropriate project time of software development so that the appraiser can be applied to the appraisal work for determining the completeness. The method is based on the manual for calculating the appropriate project period of software development project.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.4
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• pp.219-229
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• 2010

The PERT/CPM are considered as the base procedures for the most successful project scheduling programs. Unfortunately, it is not easy to apply these procedures to real-life projects. This is due to the fact that PERT/CPM assume an infinite number of resources for each activity in project networks. Obviously, the completion time under no constraints is less than when constraints are imposed. One way of approaching this problem is to use heuristic solution techniques. In this paper, we present three heuristics; MRU (Maximum Resource Use) rule, STU (Shortest Time Use) rule, MRUP (Max Resource Use and Period) rule for allocating resources to activities of projects under multiple resource constraints. Comparisons of the project durations show that these heuristic rules are superior to AG3 rule that has been widely used in practice (Elsayed and Boucher, 1994).

• Journal of Intelligence and Information Systems
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• v.6 no.2
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• pp.91-98
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• 2000

Despite their wide application of some traditional project management techniques like the Program Evaluation and Review Technique, they lack of learning, one of important factors in many disciplines today, due to a static view for project progression. This study proposes a framework for estimation by loaming based on a Linear Bayesian approach. As a project Progresses, we sequentially observe the durations of completed activities. By reflecting this newly available information to update the distribution of remaining activity durations and thus project duration, we can implement a decision support system that updates e.g., the expected project completion time as well as the probabilities of completing the project within the due bate and by a certain date. By implementing such customized system, project manager can be aware of changing project status more effectively and better revise resource allocation plans.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.3
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• pp.129-134
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• 2020

The current evaluation time period for the construction management service is the project completion or after project completion. Therefore, the construction manager has the following problems. First, it is difficult to prepare the evaluation due to the new field movement of the existing participating engineer. Next, the CM work is complex as well as extensive. Therefore, the critical success factors of the construction technology services evaluation are required as a systematic performance standard of CM work. In this study, we extracted the critical success factors that can systematically prepare the evaluation from the early stage of the project through in - depth interviews with experts. And, this study was analyze the priority of each factor by using AHP technique. As a result, the most important factors were related to the systemization of the preparation process, the construction manager work capabilities and practical construction management. And the priorities of all factors were analyzed high in the factors suggested by the owner groups. The results of this analysis are expected to provide the standards that construction management service performer carry out structured management of construction management throughout the project.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.11a
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• pp.369-374
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• 2000

Despite their tilde application of some traditional project management techniques like the Program Evaluation and Review Technique, they lack of learning, one of important factors in many disciplines today due to a static view far prefect progression. This study proposes a framework for estimation by learning based on a Linear Bayesian approach. As a project progresses, we sequentially observe the durations of completed activities. By reflecting this newly available information to update the distribution of remaining activity durations and thus project duration, we can implement a decision support system that updates e.g. the expected project completion time as well as the probabilities of completing the project within talc due date and by a certain date. By Implementing such customized systems, project manager can be aware of changing project status more effectively and better revise resource allocation plans.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.69-78
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• 2007

In real world, the project managers handle conflicting goals that govern the use of resources within the stipulated time and budget with required quality and safety. These conflicting goals are required to be optimized simultaneously by the project managers in the framework of fuzzy aspiration levels. The fuzzy linear programming model proposed herein helps project managers to minimize total project costs, completion time, and crashing costs considering indirect costs, contractual penalty costs etc by practically charging them in terms of direct cost of the project. A case study of bituminous pavement under construction is considered to demonstrate the feasibility of applying the proposed model for optimization of project parameters. Consequently, the proposed model yields an efficient compromise solution and the decision maker's overall degree of satisfaction with multiple fuzzy goal values. Additionally, the proposed model provides a systematic decision-making framework, enabling decision maker to interactively modify the fuzzy data and model parameters until a satisfactory solution is obtained. The significant characteristics that differentiate the proposed model with other models include, flexible decision-making process, multiple objective functions, and wide-ranging decision information.

• Management & Information Systems Review
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• v.13
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• pp.127-140
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• 2003

Although there have been continual researches in the project scheduling problems since 1960s, the main interest has been how to improve the efficiency of a single project. The minimization problem of the project completion time given a preassigned budget might be an example. This kind of the problem is important, but estimating of the proper budget for a project may also be very important. This research deals with the budget allocation problem for the multiple project. This research is unique in that the project scheduling techniques are used for the budgeting problem. Therefore, this research may be used as a strategic decision model for the multiple large projects in public sector.