STATISTICAL TESTING OF SOFTWARE-BASED ON A USAGE MODEL

In statistical testing, a model is developed to characterize the population of uses of the software, and the model is used to generate a statistically correct sample of all uses of the software. A software 'usage model' characterizes the population of intended uses of the software 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 usage model is based on the software specification. The model can be developed in parallel with the software, thus shortening the elapsed time required to develop the deliver software. Usage modeling has been demonstrated to be an activity that improves the specification, gives an analytical description of the specification, quantifies the testing costs and, with statistical testing, provides a basis from which inferences of software reliability may be made. This paper describes the justification for statistical testing of software using a usage model, describes procedures for developing and using a usage model and discusses several usage modeling issues and recent advances in usage model applications.