Software component reliability analysis

This paper describes an approach to analyzing software reliability using component analysis. It walks through a 6-step procedure for performing software component reliability analysis. The analysis can begin prior to testing the software and can help in selecting testing strategies. It uses the Extended Execution Time (EET) reliability growth model at the software component level. The paper describes how to estimate model parameters from characteristics of the software components and characteristics of how test cases and operational usage stress the software components. The order in which test cases are run is used in combining component models to arrive at a composite reliability growth model of the software for the testing period. The paper walks through an example illustrating the effects on reliability growth of: selecting test cases based on an operational profile versus selecting them based on uniform coverage of test cases; and incremental delivery of software components to system test. The paper contrasts the described approach to other approaches currently used to analyze software reliability growth during testing. The analysis can be done using commercial data analysis programs.