Application of Software Reliability Modeling to Product Quality and Test Process

Analysis by software reliability modeling of data taken during testing of a software system was used to predict system quality during field use. A model with predictive and descriptive validity for different phases of testing is shown. The operational profile of the system has been used as a cost effective way to drive the testing of this large scale industrial system. Differences between expected reliability and that measured during Beta Test of the system are attributed to differences in operational profile. Changes to the System Test process based on this experience are discussed with the objective of improving system quality from the users' viewpoint.