Discrere time modelling in software reliability engineering - a unified approach

In the software reliability engineering literature, few attempts have been made to measure software reliability using discrete time modeling. One of the reasons can be attributed to the mathematical complexity involved in constructing such models. The proposed unified modelling approach provides a broad framework for developing NHPP type of discrete SRGMs. The framework adopts the number of test occasions/cases as a unit of fault detection/removal period, which is countable and more appropriate measure than CPU time or calendar time used in continuous SRGMs. And classifies the faults that encountered during software testing phase into three types of faults namely, simple, hard and complex according to their removal complexity. Accordingly, their fault removal processes is modelled separately and the total fault removal phenomena is the superposition of the underlying processes. Such type of modelling approach is very much suited for object-oriented and distributed systems development environments. Actual software reliability data have been used to demonstrate the proposed framework.