Data Analysis of Step-Stress Accelerated Life Test with Random Group Effects under Weibull Distribution

Table 2

MLE results from the 600 simulated data sets when assuming σ_u = 0.7.

Parameter	Nominal value	Mean	Median	2.5% quantile	97.5% quantile
Β	0.8468	0.8465	0.8429	0.7013	1.0245
β0	35.4517	35.73	35.54	31.0406	40.8317
Β1	−3.9808	−3.976	−3.995	−4.6586	−3.4106
σu	0.7	1.5380	1.7560	−0.1753	6.0321