Jelinski Moranda model is the model of software reliability which supposes that failures occur according to the Poisson process with a rate decreasing as more faults are diagnosed. In particular if is the real failure rate per fault and N is the number of faults initially present in it, then the failure rate for the ith fault (after i - 1 faults have previously been detected, not introducing the new faults in doing so) is given as follows.