• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.293-307
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• 2003

Object-oriented development has been generalized, but object-oriented project planning and scheduling techniques have not been studied enough. Furthermore, it is difficult to apply the conventional software management techniques to object-oriented projects. Especially, the large scaled projects are increasing, but the project planing techniques for these large scaled projects have not been proposed enough. In this paper, we propose systematic techniques for OO based project scheduling. We suggest a 7 step-process for deriving the OO project schedule from the use-case diagram which is describing the functional requirements of the system. The proposed process includes identifying use-cases, drawing preliminary chart through interdependency analysis, identifying characteristics of each use case, determining the number of iteration, assigning use-cases to iteration, considering available resource and constraints, drawing revised PERT chart. Each step has the explanation of the input, output, and the guidelines needed to perform the step. The project scheduling technique proposed in this paper ran be used effectively in the planning phase which the purpose is to plan a development schedule to yield the high quality software in minimum time.

• Journal of the Korea Safety Management & Science
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• v.8 no.6
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• pp.149-157
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• 2006

This paper suggests the design and operation of value stream mapping(VSM) applied to project management, such as R&D, IT Investment. First this study represents design methodology of VSM process using SIPOC(Supplier, Input, Process, Output, Costumer). Second, this paper considers the identification and improvement plan about non-added value time for VSM using FPC(Flow Process Chart) and PERT/CPM. Last, this paper proposes VSM scheduling method using PERT/CPM and CCPM(Critical Chain Project Management)

• Journal of the Korea Institute of Building Construction
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• v.18 no.6
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• pp.595-602
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• 2018

Network-based scheduling methods can be classified into CPM method and PERT method. In the network scheduling chart, critical path can be estimated by performing the forward calculation and the backward calculation though the paths in the network chart. In PERT method, however, it is unreasonable to simply estimate the critical path by adding the sum of the activity durations in a specific path, since it does not incorporate probabilistic concept of PERT. The critical path of a PERT network can change according to the target period and deviation, and in some cases, the expected time of the critical path may not be the path with longest expected time. Based on this concept, this study proposes a technique to derive the most-likely critical path by comparing the sum of estimated time with the target time. It also proposes a method of systematically deriving all alternate paths for a network of repetitive activities. Case studies demonstrated that the most-likely critical path is not a fixed path and may vary according to the target period and standard deviation. It is expected that the proposed method of project duration forecasting will be useful in construction environment with varying target date situations.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.135-143
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• 2009

The majority of development projects fail to meet their target schedule and cost, with the overrun typically between 40 and 200 percent. These overruns happen because the planners underestimate the work or do not consider the need to rework at project planning. Representative schedule planning/management techniques such as Gantt Chart, PERT/CPM etc. that are used in domestic project planning are unable to reflect rework. This paper proposes a method to consider rework to provide more realistic estimates at schedule planning. Additionally, to prevent the underestimation of the work this paper proposes a simulation method that calculates a probabilistic estimated schedule and the associated variance based on the random variable modeling of individual task completion dates.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.89-97
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• 2003

This study is aimed at standardizing the process of spatial database construction and developing a software tool for process management. Knowhow of five GIS firms and provisions of NGI(National Geography Institute) was analyzed. In this study, the process of spatial database construction was standardized. The system from this study has the capability to manage the process of construction database using GIS and to deal with the metadata of unit map, generated from the process, systematically and continuously. The process was also shown by using either Gantt chart or PERT chart after developing an interface for "MS Project". A software "Visual Basic for Application" was used for this study.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.285-290
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• 2003

This study is aimed at standardizing the process of spatial database construction and developing a software tool for process management. Knowhow of five GIS firms and provisions of NGI(National Geography Institute) were analyzed. In this study, the process of spatial database construction was standardize. The system from this study has the capability to manage the process of construction database using GIS and to deal with the metadata of unit map, generated from the process, systematically and continuously The process was also shown by using either Gantt chart or PERT chart after developing an interface for "MS Project". A software "Visual Basic for Application" was used for this study.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.3
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• pp.28-36
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• 1982

Petri nets have been used for medeling a wide variety of systems from computer to social systems. This paper disusses Petri nets in the context of mathematical representation and its associated bag theory. The method of modeling systems such as event-condition, computer progranm computer operation and PERT chart is discribed and their Petri net representation are presented. Finally Petri net representation of tunnel diode oscillator circuit and the analysis of the circuit using Petri net are discussed with the program and results.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.355-360
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• 2004

This study is aimed at developing the system to manage the process and metadata of spatial data construction. The process of spatial data construction is standardized by analyzing knowhow of major firms and the provisions of MOCT(Ministry of the Construction and Transportation), and by appling the development methodology of information system. The system from this study has the capability to manage efficiently the process and metadata of spatial data construction. The process is shown by using index map. Also, it is shown by using Gantt chart and PERT chat after developing the interface for MS Project. The metadata is generated from the process, and managed systematically.

• The Journal of Information Systems
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• v.8 no.1
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• pp.93-108
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• 1999

The switching system is designed and developed to satisfy the performance design objectives recommended by ITU for call processing capacity and quality of service(QOS), etc. When the results by actual measurement at the system testing phase do not satisfy the performance design objectives, however, an effort is required to improve the performance. This paper presents a method for improving QOS by modifying the application programs for the switching system. In the proposed method, the sequence chart related to a delay time for call connection is modelled using PERT(Program Evaluation and Review Technique) network. Then, the criticality index of a message is calculated using Monte Carlo simulation to evaluate which message's processing time to decrease in order to decrease the delay time and thus to improve QOS. The criticality index of a block is also calculated to identify those software blocks that significantly contribute to the delay time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.141-150
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• 2012

This paper suggests a critical path search algorithm that can easily draw PERT/GANTT chart which manages and plans a project schedule. In order to evaluate a critical path that determines the project schedule, Critical Path Method (CPM) is generally utilized. However, CPM undergoes 5 stages to calculate the critical path for a network diagram that is previously designed according to correlative relationship and execution period of project execution activities. And it may not correctly evaluate $T_E$ (The Earliest Time), since it does not suggest the way how to determine the sequence of the nodes activities that calculate the $T_E$. Also, the sequence of the network diagram activities obtained from CPM cannot be visually represented, and hence Lucko suggested an algorithm which undergoes 9 stages. On the other hand, the suggested algorithm, first of all, decides the sequence in advance, by reallocating the nodes into levels after Breadth-First Search of the network diagram that is previously designed. Next, it randomly chooses nodes of each level and immediately determines the critical path only after calculation of $T_E$. Finally, it enables the representation of the execution sequence of the project activity to be seen precisely visual by means of a small movement of $T_E$ of the nodes that are not belonging to the critical path, on basis of the $T_E$ of the nodes which belong to the critical path. The suggested algorithm has been proved its applicability to 10 real project data. It is able to get the critical path from all the projects, and precisely and visually represented the execution sequence of the activities. Also, this has advantages of, firstly, reducing 5 stages of CPM into 1, simplifying Lucko's 9 stages into 2 stages that are used to clearly express the execution sequence of the activities, and directly converting the representation into PERT/GANTT chart.