Optimum release time for software systems based on reliability and cost criteria

The problem of determining the optimum time when testing can stop and the system can be considered ready for operational use is considered. This decision, of course, depends on the model for the software failure phenomenon and the criterion used for evaluating system readiness. With the time dependent error detection rate model of Goel and Okumoto, two criteria are investigated: software reliability and total expected cost. Based on the cost criterion, an optimum release policy is derived and its sensitivity to the model parameters is studied. The results are illustrated by numerical examples.