Incorporating the Testing-Effort Function into the Inflected S-Shaped NHPP Software Reliability Model

Considering testing effort and imperfect debugging in reliability modeling process may further improve the fitting and prediction results of software reliability growth models (SRGMs). For describing the S-shaped varying trend of the testing-effort increasing rate more accurately, this paper first proposes a inflected S-shaped testing effort function (IS-TEF). Then this new TEF is incorporated into the inflected S-shaped NHPP SRGMs for obtaining a new NHPP SRGMs which consider S-shaped TEF (IS-TEFM-IS). Finally the IS-TEFM-IS and several comparison NHPP SRGMs are applied into two real failure data-sets respectively for investigating the fitting power of the IS-TEFM-IS. The experimental results show that the inflected S-shaped NHPP SRGM considering IS-TEF yields the best accurate estimation results than the other comparison SRGMs.