Reliability of software with an operational profile

This article provides the stochastic and statistical framework to model software reliability in the presence of an operational profile. The software system is used under a randomly changing operational process so that the failure characteristics depend on the specific operation performed. The operational process describes, in a probabilistic sense, how the software is utilized by the users. The time to failure distribution for each fault is exponentially distributed with a rate that depends on the operation. As soon as a failure is experienced, the fault that caused the fault is removed immediately with certainty. We discuss several issues related to software reliability and statistical inference.