The energy expression is presented for a failure mechanism, and it is applied in an Accelerated Life Test (ALT) and an Accelerated Reliability Growth Test (ARGT). The conditions of the common failure mechanism are obtained. The essential relationship between the conditions and the Accelerated Factor (A f) is proposed by using the energy model. The energy expression is presented for a failure mechanism, and it is applied in an Accelerated Life Test (ALT) and an Accelerated Reliability Growth Test (ARGT). The conditions of the common failure mechanism are obtained. The essential relationship between the conditions and the Accelerated Factor (A f) is proposed by using the energy model.