Sequential Analysis of statistical science could be adopted in order to decide up on the reliable/unreliable of the developed software very quickly. Sequential analysis is different from classical hypothesis testing. In classing hypothesis testing one can draw conclusion during the data collection and final conclusion can possible be reached at a later stage, whereas sequential analysis are easy to see as data collection can be terminated after fewer cases and decision taken earlier stage, thus saving in terms of reliability of software. In this paper we proposed the performance of sequential probability ratio test (SPRT) on time domain data using exponential model and analyzed the result by applying on 3 data sets. The parameters are estimated using Modified Maximum likelihood estimation.