Two-Dimensional Software Reliability Models and Their Application

In general, the software-testing time may be measured by two kinds of time scales: calendar time and test-execution time. In this paper, we develop two-dimensional software reliability models with two-time measures and incorporate both of them to assess the software reliability with higher accuracy. Since the resulting software reliability models are based on the familiar non-homogeneous Poisson processes with two-time scales, which are the natural extensions of one-dimensional models, it is possible to treat both the time data simultaneously and effectively. We investigate the dependence of test-execution time as a testing effort on the software reliability assessment, and validate quantitatively the software reliability models with two-time scales. We also consider an optimization problem when to stop the software testing in terms of two-time measurements