• 한국통신학회논문지
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• 제36권4B호
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• pp.332-345
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• 2011

무기체계가 첨단 복합화 형태로 진화하면서 물리적 구현에서 소프트웨어가 차지하는 비중과 중요성은 급격히 증대되고 있다. 특히 네트워크 중심전(NCW)으로 대변되는 현대의 전장 상황에서 신뢰성 있게 운용되는 무기체계를 개발하기 위해서는 신뢰성 있는 소프트웨어의 개발이 필수 불가결한 요소이다. 국내 무기체계의 연구개발 과정에서 하드웨어 구성품과는 다르게 소프트웨어 요소에 대한 신뢰성 관련 기술 활동은 일부 구현된 소프트웨어에 대해 신뢰도 평가를 수행하는 수준이다. 그러나 연구개발 기간에 소프트웨어의 목표 신뢰도를 확보하기 위해서는 무기체계 개발 초기 단계부터 체계적인 신뢰성 공학 활동이 요구된다. 본 연구에서는 범위가 제약되어 있던 그 동안의 소프트웨어 신뢰성 관련 연구 활동을 무기체계 연구개발 수명주기 동안 목표 신뢰도를 만족하는 소프트웨어를 개발할 수 있도록 시스템 공학 관점에서 접근법을 제시하였다. 그 결과 무기체계의 연구개발 수명주기 동안 적용할 수 있는 프로세스를 도출하였는데 이를 무기체계의 소프트웨어 신뢰성 공학 프로세스 (Software Reliability Engineering Process for Weapon Systems: SREP-WS)로 명명하였다. 각종 첨단무기체계 개발에 도출된 SREP-WS를 적용함으로써 소프트웨어 신뢰도를 정량적 관리할 수 있고, 또한 목표 신뢰도를 개발기간 중에 확보할 수 있게 된다.

• 한국통신학회논문지
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• 제23권8호
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• pp.1915-1925
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• 1998

교환 시스템이 고장과 장애를 일으키면 서비스에 치명적인 영향을 미치게 된다. 다시 말해서 시스템을 제어하는 교환 소프트웨어의 역할은 매우 중요하다. 그렇기 때문에 정량적인 소프트웨어의 품질 평가 방법은 더욱 중요하다. 본 논문에서는 기능 블록으로 구성된 교환 소프트웨어를 시험하여 얻어진 각종 고장 데이터를 수집, 분석하고 이를 이용하여 각 버전별, 개발 전과정에 대한 소프트웨어 신뢰도를 평가해보고, 기타 고려할 사항에 대해 논한다. 대표적인 2개의 신뢰도 모형(G-O model, S-Shaped model)을 선택하여 소프트웨어 신뢰도를 비교해 보고 품질 향상을 위한 제반 활동과 소프트웨어 개발 프로젝트에 맞는 소프트웨어 신뢰도 모형을 제시하였다.

• Journal of Information Technology Applications and Management
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• 제24권2호
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• pp.71-80
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• 2017

Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.

• Nuclear Engineering and Technology
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• 제41권8호
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• pp.1065-1072
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• 2009

As the use of software increases at nuclear power plants (NPPs), the necessity for including software reliability and/or safety into the NPP Probabilistic Safety Assessment (PSA) rises. This work proposes an application procedure of software reliability growth models (RGMs), which are most widely used to quantify software reliability, to NPP PSA. Through the proposed procedure, it can be determined if a software reliability growth model can be applied to the NPP PSA before its real application. The procedure proposed in this work is expected to be very helpful for incorporating software into NPP PSA.

• International Journal of Quality Innovation
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• 제5권1호
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• pp.110-121
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• 2004

There is a new trend of incorporating software coverage metrics into software reliability modelling. This paper proposes a coverage-based software reliability growth model. Firstly, the failure rate function in coverage is analytically derived. Then it is shown that the number of detected faults follows a Nonhomogeneous Poisson distribution of which intensity function is the failure rate function in coverage. Practical applicability of the proposed models is examined by illustrative numerical examples.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.19-27
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• 2014

Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the reliability model with log type mean value function (Musa-Okumoto and log power model), which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing log type mean value function was employed. This analysis of failure data compared with log type mean value function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

• 전자통신동향분석
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• 제14권4호통권58호
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• pp.1-9
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• 1999

In this paper, we summarize the lessons learned from the applications of the software reliability engineering to a large-scale software project. The considered software is the software system of the TDX-10 ISDN switching system. The considered software consists of many components, called functional blocks. These functional blocks serve as the unit of coding and test. The software is continuing to be developed by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components to software reliability and with the analysis of the reliability evolution. We analyze the static characteristics of the software related to software reliability using failure data collected during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of software of the TDX-10 ISDN system, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto (G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources for a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.

• Journal of Information Technology Applications and Management
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• 제23권4호
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• pp.117-125
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• 2016

Software reliability in the software development process is an important issue. In infinite failure non-homogeneous Poisson process software reliability models, the failure occurrence rates per fault. can be presented constant, monotonic increasing or monotonic decreasing pattern. In this paper, the reliability software cost model considering decreasing intensity function was studied in the software product testing process. The decreasing intensity function that can be widely used in the field of reliability using power law process, log-linear processes and Musal-Okumoto process were studied and the parameter estimation method was used for maximum likelihood estimation. In this paper, from the software model analysis, we was compared by applying a software failure interval failure data considering the decreasing intensity function The decreasing intensity function model is also efficient in terms of reliability in the arena of the conservative model can be used as an alternating model can be established. From this paper, the software developers have to consider life distribution by preceding information of the software to classify failure modes which can be gifted to support.

• 산업공학
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• 제21권1호
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• pp.109-119
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• 2008

Reliability of embedded softwares, as one of factors which affect system reliability, is the probability of failure-free software operation for a specified period of time in a specified environment. and Embedded software is different from general package software because hardware and operating system are tightly coupled to each other. Reliability evaluation models for embedded softwares currently used do not separate estimation and prediction models clearly, and even a standard model has not been proposed yet. In this respect, we choose a reliability estimation model suitable for embedded softwares among software evaluation models being used, and modified the model so as to accomodate recent software environments. In addtion, based on the model, the web-based reliability prediction tool RPX is developed. Finally, an embedded software is analyzed using the tool.

• Nuclear Engineering and Technology
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• 제29권6호
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• pp.433-443
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• 1997

In this work, an analytic approach to the dependability of software in the operational phase is suggested with special attention to the hardware fault effects on the software behavior : The hardware faults considered are memory faults and the dependability measure in question is the reliability. The model is based on the simple reliability theory and the graph theory which represents the software with graph composed of nodes and arcs. Through proper transformation, the graph can be reduced to a simple two-node graph and the software reliability is derived from this graph. Using this model, we predict the reliability of an application software in the digital system (ILS) in the nuclear power plant and show the sensitivity of the software reliability to the major physical parameters which affect the software failure in the normal operation phase. We also found that the effects of the hardware faults on the software failure should be considered for predicting the software dependability accurately in operation phase, especially for the software which is executed frequently. This modeling method is particularly attractive for the medium size programs such as the microprocessor-based nuclear safety logic program.