• IE interfaces
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• v.17 no.spc
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• pp.122-130
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• 2004

Since the cost of software maintenance occupies about 50~75% in a general successful organization, the software maintenance plays an important role in software life cycle. In particular, if the managed system needs to be operated in a long term or the system is very large and complex, then the maintenance is especially more important. Software maintenance is defined as software modification activities after customer delivery, such as improvement of performance or functionality, error correction, adaptation to environmental changes, etc. In this paper, software cost estimation models are proposed, that is based on productivity of manpower in maintenance projects. In order to do this, the activities of maintenance are classified into function change, non-function change, user support and application operation. The proposed models are constructed and verified based on the real size and cost information of projects in the real world. The approach in this paper is to discriminate the heterogeneous activities in maintenance projects, and then to calculate the respective cost of each discriminated activity. By using the proposed models, the total cost of maintenance project is summed from the costs of four activities. In addition the number of conflicts between owner and order receiver about the amount of cost will be reduced and the reasonable cost estimation system will be established.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.109-123
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• 2011

The maintenance prices in information security industry between Korean companies and foreign companies have been a big difference. Korea Information Security SW maintenance standards were not adequate for the rate, and there was disagreement between domestic companies and governments. This research, therefore, surveyed a standard of information SW and the status of maintenance payment rates. The study suggests an estimation method and verifies the method and an appropriate maintenance cost rate. According to the results of the study, the current maintenance cost should be increased or decreased independent with a kind of information security systems. Based on the study, Korea government is able to change the maintenance policy in information security. And the domestic companies get a theoretical ground for improving the rates of maintenance costs in information security systems and are able to allot the resources effectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.257-262
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• 2008

This study presents a detailed analysis of aircraft engine maintenance cost based on the relationships between engine performance and geometric parameters. Some trend equations based on the engine performance and maintenance database were developed for the estimation of shop-visit interval, work-scope, man-hours, material cost and Life Limited Part cost. The results show that this approach can give a more reasonable and detailed estimation of engine maintenance cost than older empirical methods.

• Journal of Information Technology Services
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• v.16 no.2
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• pp.45-60
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• 2017

The study suggests a contract model of application operation through case study of A bank's IT outsourcing application contract based on workload. The IT outsourcing order form has a problem in that the scope of work is ambiguous due to the integration of operation and maintenance. In this study, application operation and maintenance were separated by referring to application operation history provided in ISO/IEC15504-5 standard. The scope of the IT outsourcing service was clarified by organizing the definition and detail activities of the application operation business. Application operation contract method has generally applied estimation method by the number of input manpower and period by agreement between buyer and client. As there is no activity to calculate the number of input manpower based on the operational work history and based on the standard workload per activity. In this case is not guaranteed due to the simple agreement between the contractors. In this paper, we propose an application operating cost estimation model that measures the size of the operating software using function point analysis that is the basis of application operation tasks. In order to verify the validity of the application operation cost model, we verified the correlation between the application size and the labor cost through regression analysis using SPSS.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.315-316
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• 2021

The proportion of maintenance work has been increasing due to the recent aging of the infrastructure, but the standardized construction cost estimation standards are insufficient for this. In particular, reinforced concrete structures are being applied to many structures such as buildings and bridges, and various construction methods for maintenance of reinforced concrete structures are being developed and applied. In this study, we surveyed about the current status of the construction method for the maintenance work of reinforced concrete structures and analyze the factors of the revision of the construction cost estimate standard for the reinforced concrete structure maintenance.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.232-237
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• 2008

Several research institutes including KISTEC and KRRI etc., recently, have studied maintenance activities and performance, in order to determine proper maintenance level and maintenance cost of rail tracks. But it may extremely difficult to make a decision in maintenance matters of concrete track and ballast containing other sub-components. For these reasons, this study investigate variables related to current maintenance, essential maintenance, and preventive maintenance. It is intended to suggest estimation method of proper maintenance cost maximizing rail track performance. It is stated that proposed approach may be very useful to make a decision of proper maintenance level. Typical section of rail track is applied for calculation of life cycle cost according to each maintenance strategy. A proper profile for maintenance is determined minimum life cycle

• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.97-114
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• 2002

An estimation of economic life for a new weapon system is a critical issue in aquisition process. In general a life cycle cost consists of, development cost, aquisition cost, and maintenance cost. These costs are not identified and obtained in the beginning of the aquisition process. This paper deals with an economic life for KlAl tank which is being deployed recently, using PRICE model. In order to estimate an KlAl economic life, we use equivalent annual cost method which is sum of capital recovering with return and equivalent O&M cost method. This method determines an economic life by minimizing annual investment cost and operation and maintenance cost. In this paper, an aquisition cost of KlAl is obtained from PRICE H and O&M cost from PRICE HL model. We obtained various results depending upon production quantity. An economic life for KlAl is estimated 18 years when 300 tanks are produced.

• Journal of Applied Reliability
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• v.16 no.4
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• pp.280-286
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• 2016

Purpose: Recently, Jiang defines the tradeoff B life to minimize a sum of life lost by preventive maintenance (PM) and corrective maintenance (CM) contribution parts and sets up an optimal replacement age of age replacement policy as this tradeoff life. In this paper, Jiang's model only considering the known lifetime distribution is extended by assigning different weights to two parts of PM and CM in order to reflect the practical maintenance situations in application. Methods: The new age replacement model is formulated and the meaning of a weight factor is expressed with the implied cost of failure under asymptotic expected cost model and also discussed with one-cycle expected cost criterion. Results: The proposed model is applied to Weibull and lognormal lifetime distributions and optimum PM replacement ages are derived with corresponding implied cost of failure. Conclusion: The new age replacement policy to escape the estimation of cost of failure in classical asymptotic expected cost criterion based on the renewal process is provided.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.250-251
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• 2019

Lots of infrastructures have been newly constructed through the rapid economic growth of 1970's. Since the infrastructures has mostly deteriorated and this circumstance makes the need for maintenance and rehabilitation(M&R) of infrastructures to obtain the convenience and safety of users even more essential. Although markets for M&R project become larger, the construction standards for cost estimation of M&R work are insufficient. Thus, the purpose of this study is to examine the present state of standards for cost estimation of M&R works using case studies. Finally, this work could be utilized as the basis for the development of national standard for estimation of M&R work.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.717-724
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• 2018

To prepare for the explosive increase in maintenance costs of bridges according to the aging of infrastructure, future maintenance costs of bridges should be predicted. For this purpose, the management status of bridges was investigated and modeled as the upper limit of the performance level and the target management level according to the life cycle. This paper proposes methodologies and procedures for estimating the bridge maintenance costs using two models and existing cost and performance prediction models that consist of unit repair cost model according to the safety score, performance degradation model of bridges, unit reconstruction cost, and average reconstruction time. To verify the applicability, future maintenance costs can be forecasted for specific management agency considering the number of bridges, degree of aging, and current management status. As a result, it is possible to obtain the maintenance cost and safety level of an individual bridge level for each year. In addition, by summing them up to the agency level, the average safety score, ratio of the safety level, inspection costs, repair costs, and reconstruction costs can be obtained. In a further study, the changes in maintenance costs can be analyzed according to the changes in the target management levels using the developed method. The optimal management level can be suggested by reviewing the results.