Operational Profile Specification, Test Case Generation, and Reliability Estimation for Modules

Dr. Denise M. Woit

Software Engineering Research Group
CRL, McMaster University,
Hamilton, Ontario, Canada L8S 4K1


This report explores both practical and theoretical problems associated with module reliability estimation. It describes a technique for specifying operational profiles for modules. The technique is more general than those of the current literature and allows more accurate specification of module usage. We also outline our algorithm and software tool for automatically generating random test cases from an operational profile specification for a module. The test cases correspond to a random sampling of the module, consistent with the operational profile and hence similar to the expected actual operation. Statistical estimations such as operational reliability, will be more meaningful when the specification method and generation algorithm are used, because our method permits precise specifications of the environmental conditions in which the module will operate.

This report also presents a method for estimating module reliability that is based on statistical hypothesis testing. All estimates are based on the current version of the module. The method is applicable even when the current version has not yet failed any tests.