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Tadashi Dohi - One of the best experts on this subject based on the ideXlab platform.

  • estimating software intensity function based on translation invariant Poisson smoothing approach
    IEEE Transactions on Reliability, 2013
    Co-Authors: Xiao Xiao, Tadashi Dohi
    Abstract:

    Because the software failure occurrence Process is well-modeled by a non-Homogeneous Poisson Process, it is of great interest to estimate accurately the software intensity function of Non-Homogeneous Poisson Process (NHPP)-based software reliability models (SRM) from observed software-fault count data. In recent years, wavelet-based techniques have been well established in Poisson intensity estimation because of their technical advantages of computational cost and accuracy. The approach enables us to carry out the analysis of a software debugging Process in a nonparametric way. In this paper, we propose an applied Haar wavelet-based approach which is without an approximate data transformation, for software reliability assessment. In a numerical study with real software-fault count data, we compare the proposed estimation method with the previously used data transformation-based estimation method, as well as conventional maximum likelihood estimation and least squares estimation methods. Furthermore, we conduct sensitivity analysis of the resolution level, which affects the estimation accuracy of the proposed method. We also estimate some predictive measures such as software reliability.

  • quantitative security evaluation for software system from vulnerability database
    Journal of Software Engineering and Applications, 2013
    Co-Authors: Hiroyuki Okamura, Masataka Tokuzane, Tadashi Dohi
    Abstract:

    This paper proposes a quantitative security evaluation for software system from the vulnerability data consisting of discovery date, solution date and exploit publish date based on a stochastic model. More precisely, our model considers a vulnerability life-cycle model and represents the vulnerability discovery Process as a non-Homogeneous Poisson Process. In a numerical example, we show the quantitative measures for contents management system of an open source project.

  • wavelet shrinkage estimation for non Homogeneous Poisson Process based software reliability models
    IEEE Transactions on Reliability, 2013
    Co-Authors: Xiao Xiao, Tadashi Dohi
    Abstract:

    We develop a novel estimation approach for quantitative software reliability by means of wavelet-based technique, where the underlying software reliability model is described by a non-Homogeneous Poisson Process. Our approach involves some advantages over the commonly used techniques such as maximum likelihood estimation: 1) the wavelet shrinkage estimation enables us to carry out the time-series analysis with high speed and accuracy requirements; and 2) The wavelet shrinkage estimation is classified into a non-parametric estimation without specifying a parametric form of the software intensity function. We consider data-transform-based wavelet shrinkage estimation with four kinds of thresholding schemes for empirical wavelet coefficients to estimate the software intensity function. In numerical experiments with real software-fault count data, we show that our wavelet-based estimation methods can provide better goodness-of-fit performance than not only the conventional maximum likelihood estimation and least squares estimation but also the local likelihood estimation method, in many cases, in spite of their non-parametric nature. Furthermore, we investigate the predictive performance of the proposed methods by employing the so-called one-stage look-ahead prediction method, and estimate some predictive measures such as software reliability.

Mohammad G M Khan - One of the best experts on this subject based on the ideXlab platform.

  • a study of testing effort dependent inflection s shaped software reliability growth models with imperfect debugging
    International Journal of Quality & Reliability Management, 2010
    Co-Authors: N Ahmad, Mohammad G M Khan, Loriza S Rafi
    Abstract:

    Purpose – The purpose of this paper is to investigate how to incorporate the exponentiated Weibull (EW) testing‐effort function (TEF) into inflection S‐shaped software reliability growth models (SRGMs) based on non‐Homogeneous Poisson Process (NHPP). The aim is also to present a more flexible SRGM with imperfect debugging.Design/methodology/approach – This paper reviews the EW TEFs and discusses inflection S‐shaped SRGM with EW testing‐effort to get a better description of the software fault detection phenomenon. The SRGM parameters are estimated by weighted least square estimation (WLSE) and maximum‐likelihood estimation (MLE) methods. Furthermore, the proposed models are also discussed under imperfect debugging environment.Findings – Experimental results from three actual data applications are analyzed and compared with the other existing models. The findings reveal that the proposed SRGM has better performance and prediction capability. Results also confirm that the EW TEF is suitable for incorporating...

  • the exponentiated weibull software reliability growth model with various testing efforts and optimal release policy a performance analysis
    International Journal of Quality & Reliability Management, 2008
    Co-Authors: N Ahmad, S M K Quadri, Mohammad Ubaidullah Bokhari, Mohammad G M Khan
    Abstract:

    Purpose – The purpose of this research is to incorporate the exponentiated Weibull testing‐effort functions into software reliability modeling and to estimate the optimal software release time.Design/methodology/approach – This paper suggests a software reliability growth model based on the non‐Homogeneous Poisson Process (NHPP) which incorporates the exponentiated Weibull (EW) testing‐efforts.Findings – Experimental results on actual data from three software projects are compared with other existing models which reveal that the proposed software reliability growth model with EW testing‐effort is wider and effective SRGM.Research limitations/implications – This paper presents a SRGM using a constant error detection rate per unit testing‐effort.Practical implications – Software reliability growth model is one of the fundamental techniques to assess software reliability quantitatively. The results obtained in this paper will be useful during the software testing Process.Originality/value – The present schem...

Xiao Xiao - One of the best experts on this subject based on the ideXlab platform.

  • estimating software intensity function based on translation invariant Poisson smoothing approach
    IEEE Transactions on Reliability, 2013
    Co-Authors: Xiao Xiao, Tadashi Dohi
    Abstract:

    Because the software failure occurrence Process is well-modeled by a non-Homogeneous Poisson Process, it is of great interest to estimate accurately the software intensity function of Non-Homogeneous Poisson Process (NHPP)-based software reliability models (SRM) from observed software-fault count data. In recent years, wavelet-based techniques have been well established in Poisson intensity estimation because of their technical advantages of computational cost and accuracy. The approach enables us to carry out the analysis of a software debugging Process in a nonparametric way. In this paper, we propose an applied Haar wavelet-based approach which is without an approximate data transformation, for software reliability assessment. In a numerical study with real software-fault count data, we compare the proposed estimation method with the previously used data transformation-based estimation method, as well as conventional maximum likelihood estimation and least squares estimation methods. Furthermore, we conduct sensitivity analysis of the resolution level, which affects the estimation accuracy of the proposed method. We also estimate some predictive measures such as software reliability.

  • wavelet shrinkage estimation for non Homogeneous Poisson Process based software reliability models
    IEEE Transactions on Reliability, 2013
    Co-Authors: Xiao Xiao, Tadashi Dohi
    Abstract:

    We develop a novel estimation approach for quantitative software reliability by means of wavelet-based technique, where the underlying software reliability model is described by a non-Homogeneous Poisson Process. Our approach involves some advantages over the commonly used techniques such as maximum likelihood estimation: 1) the wavelet shrinkage estimation enables us to carry out the time-series analysis with high speed and accuracy requirements; and 2) The wavelet shrinkage estimation is classified into a non-parametric estimation without specifying a parametric form of the software intensity function. We consider data-transform-based wavelet shrinkage estimation with four kinds of thresholding schemes for empirical wavelet coefficients to estimate the software intensity function. In numerical experiments with real software-fault count data, we show that our wavelet-based estimation methods can provide better goodness-of-fit performance than not only the conventional maximum likelihood estimation and least squares estimation but also the local likelihood estimation method, in many cases, in spite of their non-parametric nature. Furthermore, we investigate the predictive performance of the proposed methods by employing the so-called one-stage look-ahead prediction method, and estimate some predictive measures such as software reliability.

N Ahmad - One of the best experts on this subject based on the ideXlab platform.

  • a study of testing effort dependent inflection s shaped software reliability growth models with imperfect debugging
    International Journal of Quality & Reliability Management, 2010
    Co-Authors: N Ahmad, Mohammad G M Khan, Loriza S Rafi
    Abstract:

    Purpose – The purpose of this paper is to investigate how to incorporate the exponentiated Weibull (EW) testing‐effort function (TEF) into inflection S‐shaped software reliability growth models (SRGMs) based on non‐Homogeneous Poisson Process (NHPP). The aim is also to present a more flexible SRGM with imperfect debugging.Design/methodology/approach – This paper reviews the EW TEFs and discusses inflection S‐shaped SRGM with EW testing‐effort to get a better description of the software fault detection phenomenon. The SRGM parameters are estimated by weighted least square estimation (WLSE) and maximum‐likelihood estimation (MLE) methods. Furthermore, the proposed models are also discussed under imperfect debugging environment.Findings – Experimental results from three actual data applications are analyzed and compared with the other existing models. The findings reveal that the proposed SRGM has better performance and prediction capability. Results also confirm that the EW TEF is suitable for incorporating...

  • the exponentiated weibull software reliability growth model with various testing efforts and optimal release policy a performance analysis
    International Journal of Quality & Reliability Management, 2008
    Co-Authors: N Ahmad, S M K Quadri, Mohammad Ubaidullah Bokhari, Mohammad G M Khan
    Abstract:

    Purpose – The purpose of this research is to incorporate the exponentiated Weibull testing‐effort functions into software reliability modeling and to estimate the optimal software release time.Design/methodology/approach – This paper suggests a software reliability growth model based on the non‐Homogeneous Poisson Process (NHPP) which incorporates the exponentiated Weibull (EW) testing‐efforts.Findings – Experimental results on actual data from three software projects are compared with other existing models which reveal that the proposed software reliability growth model with EW testing‐effort is wider and effective SRGM.Research limitations/implications – This paper presents a SRGM using a constant error detection rate per unit testing‐effort.Practical implications – Software reliability growth model is one of the fundamental techniques to assess software reliability quantitatively. The results obtained in this paper will be useful during the software testing Process.Originality/value – The present schem...

R C Dahiya - One of the best experts on this subject based on the ideXlab platform.

  • estimating the parameters of a non Homogeneous Poisson Process model for software reliability
    IEEE Transactions on Reliability, 1993
    Co-Authors: S A Hossain, R C Dahiya
    Abstract:

    A stochastic model (G-O) for the software failure phenomenon based on a nonHomogeneous Poisson Process (NHPP) was suggested by Goel and Okumoto (1979). This model has been widely used but some important work remains undone on estimating the parameters. The authors present a necessary and sufficient condition for the likelihood estimates to be finite, positive, and unique. A modification of the G-O model is suggested. The performance measures and parametric inferences of the new model are discussed. The results of the new model are applied to real software failure data and compared with G-O and Jelinski-Moranda models. >