Pragmatic study of parametric decomposition models for estimating software reliability growth

Numerous stochastic models for the software failure phenomenon based on Nonhomogeneous Poisson Process (NHPP) have been proposed in the recent three decades. Although these models are quite helpful for software developers and have been widely applied in the industrial organizations or research centers, we still need to do more works on examining/estimating the parameters of existing software reliability growth models (SRGMs). In this paper, we investigate and account for three possible trends of software fault detection phenomenon during the testing phase: increasing, decreasing and steady state. We present empirical results from the quantitative studies on evaluating the fault detection process and develop a valid time-variable fault detection rate model which has the inherent flexibility of capturing a wide range of possible fault detection trends. The applicability of the proposed model and the related methods of parametric decomposition are illustrated through several real data sets from different software projects. Our evaluation results show that the analytic parametric decomposition approach for SRGM have a fairly accurate predicting capability. In addition, the testing-effort control problem based on the proposed model is also demonstrated.