STATISTICAL TESTING OF SOFTWARE-BASED ON A USAGE MODEL

In statistical testing, a model is developed to characterize the popul ation of uses of the software, and the model is used to generate a sta tistically correct sample of all uses of the software. A software 'usa ge model' characterizes the population of intended uses of the softwar e in the intended environment. Statistical testing based on a software usage model ensures that the failures that will occur most frequently in operational use will be found early in the testing cycle. The usag e model is based on the software specification. The model can be devel oped in parallel with the software, thus shortening the elapsed time r equired to develop the deliver software. Usage modeling has been demon strated to be an activity that improves the specification, gives an an alytical description of the specification, quantifies the testing cost s and, with statistical testing, provides a basis from which inference s of software reliability may be made. This paper describes the justif ication for statistical testing of software using a usage model, descr ibes procedures for developing and using a usage model and discusses s everal usage modeling issues and recent advances in usage model applic ations.