The software project manager must plan and conduct testing activities economically and efficiently. Due to the constraints, such as limited testing resources, delivery time, and cost, it isn’t easy to conclude. The software reliability growth models (SRGMs) based on testing-effort, help the project manager in the decision process. Therefore, we reckon the testing effort function (TEF) during model formulation. This paper introduces a new model for estimating the growth of software reliability. This model incorporates generalized inflection S-shaped (GISS) distribution for TEF. Here, the TEF is involved as a time-dependent failure rate function. Besides, the developed model is in perfect debugging environment. Here, we estimate the values of the unknown parameters by the least square estimation (LSE). All the performance measures are calculated using real software failure data-set and comparisons made between the proposed model and the existing models. It is noted that the performance of the proposed model prediction for the total number of faults is more trustworthy.