• 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 Korea Society of Computer and Information
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• v.16 no.9
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• pp.35-43
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• 2011

To develop a software, there is a relationship between development organization's productivity, effort, development schedule, and software size. It is software equation that motive these relations. Basically, relationship between size-effort and size-schedule is applied. If this relationship is not proper, there would be no effect of the cost-schedule tradeoff equation that is derived from software equation, and the manpower profile analysis, etc. To solve these unwanted problems, we presented a modified software equation and a cost-schedule tradeoff model based on the modified software equation. To improve software development success rate, applying proposed model will help in contract negotiation or bid.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.155-164
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• 2012

The compression of software development schedule has a limit without regarding to a development manpower. However, the actually developed softwares includes the impossible short time or unreal long time date. Previously suggested models are driving the development schedule from all of the actually developed software without considering these constraints. This paper recommends a standard of minimum and the most suitable development time period. This paper has chosen a criterion that shows the best development schedule among 5 criteria based on the actually performed projects. Moreover, this paper suggests a model that estimates the development schedule based on the best criterion.

• Journal of KIBIM
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• v.9 no.2
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• pp.1-10
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• 2019

In this research, schedule optimization is defined as balancing the number of workers while keeping the demand and needs of the project resources, creating the perfect schedule for each activity. Therefore, when one optimizes a schedule, multiple potentials of schedule changes are assessed to get an instant view of changes that avoid any over and under staffing while maximizing productivity levels for the available labor cost. Optimizing the number of workers in the scheduling process is not a simple task since it usually involves many different factors to be considered such as the development of quantity take-offs, cost estimating, scheduling, direct/indirect costs, and borrowing costs in cash flow while each factor affecting the others simultaneously. That is why the optimization process usually requires complex computational simulations/modeling. This research attempts to find an optimal selection of daily maximum workers in a project while considering the impacts of other factors at the same time through OPEN BIM based multiple computer simulations in resource leveling. This paper integrates several different processes such as quantity take-offs, cost estimating, and scheduling processes through computer aided simulations and prediction in generating/comparing different outcomes of each process. To achieve interoperability among different simulation processes, this research utilized data exchanges supported by building SMART-IFC effort in automating the data extraction and retrieval. Numerous computer simulations were run, which included necessary aspects of construction scheduling, to produce sufficient alternatives for a given project.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.137-146
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• 2022

In relation to the travel itinerary recommendation service, which has recently become in high demand, our previous work introduces a method to quantify the popularity of places including tour spots, restaurants, and accommodations through social big data analysis, and to create a travel schedule based on the analysis results. On the other hand, the generated schedule was mainly composed of travel routes that connected tour spots with the shorted distance, and detailed schedule information including restaurants and accommodation information for each travel date was not provided. This paper presents an algorithm for constructing a detailed travel route using a scenario template in a travel schedule created based on social big data, and introduces a prototype system that implements it. The proposed system consists of modules such as place information collection, place-specific popularity score estimation, shortest travel rout generation, daily schedule organization, and UI visualization. Experiments conducted based on social reviews collected from 63,000 places in the Gyeongnam province proved effectiveness of the proposed system.

• Journal of Digital Contents Society
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• v.16 no.4
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• pp.555-564
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• 2015

Since the size of the construction project has become massive, complicated and specialized, the use for a substantial amount of information provided from diverse participants is considered important. Schedule information obtained from a variety of sources is key during the construction project. Misunderstanding of schedule management information causes delay of construction period and low quality of construction. Currently, interest in BIM (Building Information Modeling) that produces the necessary data for the entire life cycle of the building process is rising. The study is to construct the BIM-base-information system in order to systematically manage schedule information of the construction work. For this purpose, the study established a BIM-base-schedule-management-business process and drew a classification system for the work for schedule-information construction. The study also drew information that can be extracted from the BIM model among properties required to build certain information. The schedule is made upon consideration of information needed for schedule management, and information required to schedule a timeline of the construction project by process is established.

• Journal of the Korea Institute of Building Construction
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• v.11 no.1
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• pp.1-8
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• 2011

Linear scheduling method limits to present works of work breakdown structure as a form of lines and was often developed manually. In other words, linear schedule could not utilize activity, work breakdown structure, and etc. information of network schedule such as CPM(Critical Path Method) and has been used only for reporting or confirming construction master plan. Therefore, it is necessary to develop system which can automatically generating the linear schedule based on the network schedule having many accumulated and useful construction schedule information. Thus, this research has an effort to establish data process model, data flow diagram, and data model in order to make linear schedule. In addition, this research addresses the system solution structure, user interface class diagram and logic diagram, and data type schema. The results of this paper can be used as a preliminary research for developing linear schedule generating system prototype by utilizing the network schedule information.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.268-271
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• 2000

In these days, the technical advances and complexities have generated much of the difficulties in managing the project resources, both time and costing to accomplish the project in the most efficient manner. The project manager is frequently required to render judgements concerning the schedule and resource adjustments. This research develops an analytical model for a schedule-cost and risk analysis based on visual PERT/CPM. We used a two-step approaches ：in the step 1, a deterministic PERT/CPM model for the critical path and estimating the project time schedule and related resource planning, In the second step, we developed a heuristic model for crash and stretch out analysis based upon a time-cost trade-off associated with the crash and stretch out of the project. Computer implementation of this model is provided based on GUI-Type objective-oriented programming for the users and provided displays of all the inputs and outputs in the form of visual graphical. Also developed GUI-type program, Dongeui Visual-PERT/CPM. The results of this research will provide the project managers with an efficient management tool.

• IE interfaces
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• v.25 no.2
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• pp.216-228
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• 2012

BIM-based 4D simulation makes people easily understand complex construction process using 3D graphics model and helps them review and identify the construction schedule in each phase of the construction process. Moreover, 4D simulation can be used as reference data to determine the validity of the process in the design phase and will be utilized as a measure for checking the construction process. Therefore 4D simulation of construction improves efficiency of project management. However, current commercial applications available for 4D simulation do not provide sufficient functions for connection of 3D models and process information. In this paper, we propose an automated generation method through the definition of the process based on a work method template and developed the template based schedule generation system (TSGS).

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1132-1137
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• 2008

Automatic Operation based on ATO (Automatic Train Operation) is necessary for driverless Light Rail Transit business. When this kind of driverless LRT operation plan is made, TPS (Train Performance Simulation) is traditionally simulated at all-out mode and coasting mode based on manual operation. Commercial schedule speed equals to all-out speed minus $9{\sim}15%$ make-up margin. Coasting mode TPS simulation is also run at commercial schedule speed to calculate run time and energy consumption. But TPS based on manual operation should make an improvement on accuracy in case of driverless LRT operation Plan. In this paper, new fast mode TPS simulation using ATO pattern is proposed and show near actual ATO result. The actual ATO pattern can be accurately simulated with the introduction of 4 parameters such as commercial braking rate, jerk, station stop profile and grade converted distance. Normal mode TPS simulation for commercial schedule speed can be designed to have fast mode trip time plus 3 seconds/km margin recommended by korean standard LRT specification.