A study of the sensitivity of software release time

Software release time determination is of great importance to software developers. In order to predict the amount of testing needed and to estimate the release time at which a certain reliability target is met, probabilistic models can be used to predict the reliability level achieved during the software testing. However, most of the results assume that the model parameters are known which is not true since they have to be estimated based on the information available. In many cases, they are inaccurate because of the small amount of data available. Hence, it is useful to know the sensitivity of software release time with respect to the estimated parameters so that attention can be paid to those parameters that affect the release time significantly. In this paper, the sensitivity issue is studied for a commonly used software reliability model. The study can be used, for example, if an overestimation of a parameter implies an underestimation of the release time which can be costly as more failures are experienced by the consumers, we should try not to overestimate that parameter. Also, if a parameter affects the release time more than others, it is important to have this parameter estimated as accurately as possible. The interval estimation of release time is recommended to avoid further excessive adjustment of release time. (C) 1998 Elsevier Science Inc. All rights reserved.