Reliability Modeling for Systems with Multiple Degradation Processes Using Inverse Gaussian Process and Copulas

Table 5

Goodness-of-Fit for the four copulas.

Copula	Parameter Estimation	AIC	Kendall’s tau	Spearman’s rho	Ranking
Gumbel	1.5150	−1114.89	0.3399	0.4836	2
Frank	3.9127	−1118.13	0.3816	0.5487	1
Clayton	0.3544	−1095.96	0.1505	0.2241	6
Gaussian	0.4880	−1112.91	0.3246	0.4708	3
Joe	1.7663	−1112.25	0.2985	0.4294	4
Amh	0.8235	−1108.12	0.2436	0.3590	5