Enhancing and measuring the predictive capabilities of testing-effort dependent software reliability models

Software testing is necessary to accomplish highly reliable software systems. If the project manager can conduct well-planned testing activities, the consumption of related testing-resources will be cost-effective. Over the past 30 years, many software reliability growth models (SRGMs) have been proposed to estimate the reliability growth of software, and they are mostly applicable to the late stages of testing in software development. Thus far, it appears that most SRGMs do not take possible changes of testing-effort consumption rates into consideration. However, in some cases, the policies of testing-resource allocation could be changed or adjusted. Thus, in this paper, we will incorporate the important concept of multiple change-points into Weibull-type testing-effort functions. The applicability and performance of the proposed models are demonstrated through two real data sets. Experimental results show that the proposed models give a fairly accurate prediction capability. Finally, based on the proposed SRGM, constructive rules are developed for determining optimal software release times. (C) 2007 Elsevier Inc. All rights reserved.