Using Reliability Models During Testing With Non-Operational Profiles*

Operational profile is a set of relative frequencies of occurrence of the run categories associated with the product and its operational use. During operation system executes a series of runs which are selected from the available run categories at random (but according to the operational profile). Software (and system) reliability growth models model the fault removal process during product testing in order to make inferences about its behavior in operation. Practically all available software reliability models assume failure detection based on operational profiles. This assumption is usually violated during early software testing phases (e.g., unit testing and integration testing phases). Consequently, Software Reliability Engineering assessment and control of project or product quality growth during non-operational testing stages requires consideration of several factors, and interpretation of classical software reliability models becomes difficult and may be deceptive. Models specifically tailored for evaluation of non-operational testing are needed.