“…To illustrate the proposed methods, a real data is selected from Ebrahimi [25], of which the accelerated stress is voltage, the stress levels are S 1 � 10V, S 2 � 15V, and S 3 � 20V, and the normal stress level is S 0 � 5V. Furthermore, for each stress level, the life tests are allowed to run over the time (τ 1 , τ 2 , τ 3 ) � (2, 1.5, 1), the numbers under the test were (n 1 , n 2 , n 3 ) � (15,15,15), the expected failure number are (m 1 , m 2 , m 3 ) � (11,12,13), and the progressive censoring scheme is R and 3.…”