Power cycling is a testing method for power semiconductor devices wherein switching functions are simulated to generate heat and raise junction temperature instead of using a chamber. Failure analysis of devices following the test can provide valuable insight into the failure modes and mechanisms of power electronic devices. Most switching applications do not operate continuously, particularly in transportation and energy sectors. Applications of power electronics such as electric trains, wind turbines, and solar inverters have long nonoperational periods in their life cycle profiles. This work introduces periods of dormancy into a power-cycling test to study the effects of the dormancy on failure mechanisms. During the dormant periods, void growth is monitored in the IGBT die attach. The differences in failure mechanisms and degradation patterns between continuous power cycling and intermittent power cycling with dormancy are being investigated for the two types of tests, and suggestions for modifications to industry standards are being developed.