• Journal of Korea Society of Industrial Information Systems
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• 제2권1호
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• pp.177-201
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• 1997

In this paper, a model of cost evaluatino for computer software development is proposed . This model is designed to cope with various development environment since the development cost is directly dependent on the development environments. The model that satisfies the users request is turned out to be a function point model. For the future research , a model that contain new technique and new development environment and an imaginative model are desired . Also, in order to effective cost estimation a systematic research on structure of software development , establishment of standard development methodology, project management and technique are desired.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1170-1175
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• 2009

When managers estimate exact construction cost at early stage and design phase, they can reduce construction cost in a more efficient way than to predict at construction stage. But, the current of public construction cost estimation and management is concentrated almost after detailed design phase. Therefore, construction cost management in design development phase to generally use approximate estimating is not correct. Also, the existing construction cost used the method that estimated by gross floor area-based cost estimates at design development phase. So, it is difficult to show the specific amount of materials and basis about the estimated cost of the construction. This study derived problems and limits of construction management at design development phase in case of public office building project through review of literature and current survey, and suggested estimating process model process of structural construction cost go improve these matters.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• 제12권6호
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• pp.554-560
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• 2019

In this study, after applying the finite failure NHPP Rayleigh distribution model and NHPP Inverse Rayleigh distribution model which are widely used in the field of software reliability to the software development cost model, the attributes of development cost and optimal release time were compared and analyzed. To analyze the attributes of software development cost, software failure time data was used, parametric estimation was applied to the maximum likelihood estimation method, and nonlinear equations were calculated using the bisection method. As a result, it was confirmed that Rayleigh model is relatively superior to Inverse Rayleigh model because software development cost is relatively low and software release time is also fast. Through this study, the development cost attributes of the Rayleigh model and the Inverse Rayleigh model without the existing research examples were newly analyzed. In addition, we expect that software developers will be able to use this study as a basic guideline for exploring software reliability improvement method and development cost attributes.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제39권6호
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• pp.576-584
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• 2011

In order to develop a launch vehicle successfully, it is important to estimate development costs accurately but it is also important to plan the annual budget. In this paper, the statistical method was utilized for cost spreading. For cost spread modeling, the suitability of the model by analyzing several statistical models was evaluated and consequently, the beta-distribution model has been selected. In this study, the validity of the annual estimation cost model was verified through the comparison of the actual development cost distribution and the estimating cost distribution of Space Shuttle Main Engine. In addition, this paper estimated the annual budget required for the development of the KSLV-II using currently allocated cost for successful development. It is anticipated that the present cost spread model can be applied to not only launch vehicle development but also other large complex system development.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2002년도 학술대회지
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• pp.419-422
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• 2002

The features of modem construction industry can be summarized as specialization, complexity, and large-scale. Therefore, increasing uncertainty of construction project can not be effectively dealt with traditional method used for construction cost management. Cost overrun affects on successful execution of managing construction project in a negative way. Therefore, accurate estimation is a priori for effective cost management. First, this work analyzes the previous cost estimation model for the effective cost management. Then, a standard structure required for developing the cost estimation model for site development was presented. In addition, the cost estimation model which can be used in planning and design phases was introduced by analyzing real site development projects.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.359-364
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• 1999

Providing the reasonable construction cost at the initial stage of the rural development project, is a kety factor of the each step of project , such as propriety analysis , cost planning , design, and planning the progress of work. The explainable construction cost can be estimated at the early stage using the actual cost data by statistical analysis. In this study, the influence factors are extracted by factor analysis with the actual cost data of rural development project, object cost model is developed by multiple regression analysis, and verify the developed cost model by Monte-Carlo simulation .

• The Journal of the Korea institute of electronic communication sciences
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• 제18권5호
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• pp.935-944
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• 2023

In this study, the Inverse-type (: Inverse-Exponential, Inverse-Rayleigh) life distribution, which is known to be suitable for reliability research, was applied to a software development cost model based on finite failure NHPP(: Nonhomogeneous Poisson Process), and then the attributes that determine the model's performance were analyzed. Additionally, to evaluate the efficiency of the model, it was compared with the Goel-Okumoto basic model. The performance of the model was analyzed using failure time data, and MLE (: Maximum Likelihood Estimation) was applied to calculate the parameters. In conclusion, first, as a result of analyzing m(t), which determines the development cost, the Inverse-Exponential model was efficient due to its small error in the true value. Second, as a result of analyzing the release time along with the development cost, the Inverse-Rayleigh model was confirmed to be the best. Third, as a result of comprehensive evaluation of the attributes (m(t), cost, and release time) of the proposed model, the Inverse-Rayleigh model had the best performance. Therefore, if software developers can effectively utilize this research data in the early process, they will be able to proactively explore and analyze attributes that affect cost.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.305-312
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• 1999

This study is intended to propose a systematic and practical life cycle cost(LCC) model for the development of the reliability-based seismic safety and cost-effective performance criteria for design and upgrading of long-span PC bridges. The LCC models consist of five cost functions such as initial cost, repair/replacement cost, human losses, road user cost, and indirect losses of regional economy. The proposed model Is successfully expressed in temrs of Park-Ang damage indices and life cycle damage probability obtained from SMART-DRAIN-2DX which is an existing algorithm for nonlinear time history analysis. The proposed LCC model is successfully applied to a viaduct constructed by PSM, in Seoul. Based on the observations, the proposed systematic procedure for the formulation of LCC model may be useful for the development of the reliability-based seismic safety and cost-effective performance criteria for design and upgrading of long-span PC bridges.

• Journal of Integrative Natural Science
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• 제9권3호
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• pp.206-214
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• 2016

The basic goal of software development is to produce high quality software at low cost. Therefore, when to stop software testing and release the software product is a significant point in the software development. The software cost model is an effective tool used to help software developers control costs and determine the release time. In this paper, we discuss the cost model to apply all 6 models with consideration of time to remove errors, cost of removing each error and risk cost due to software failure. We show the impact of cost coefficients and parameter values on the expected total cost by changing the values and comparing the optimal release times.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• 제11권4호
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• pp.460-466
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• 2018

With the development of information technology, the scale of computer software system is constantly expanding. Reliability and cost of software development have a great impact on software quality. In this study, based on the software failure interval time data, a comparative analysis was performed on the characteristics of the software development cost model based on the lifetime distribution following the Type-2 Gumbel and Erlang distribution in the NHPP model. As a result, the trends of the cost curves for the Go-Okumoto model and the proposed Erlang model and the Type-2 Gumble model both decreased in the initial stage and gradually increased in the latter half of the failure time. Also, Comparing the Erlang model with the Type-2 Gumble model, we found that the Erlang model is faster and more cost-effective at launch. Through this study, Software operators should remove possible defects from the testing phase rather than the operational phase to reduce defects after the software release date, it is expected to be able to study the prior information needed to understand the characteristic of software development cost.