“…In 1955, Cox [1] first proposed the "supplementary variable technique (SVT)" and established the M/G/1 queuing system. Gaver [2] was the first to apply this technique for reliability models, and subsequently, other authors followed this line of research, such as Linton [3], Gupta and Gupta [4], Shi and Li [5], Chung [6], Oliveira et al [7], Zhang and Wu [8], Shakuntla et al [9], Singh et al [10], Ke et al [11], Shekhar et al [12], Gao and Wang [13].…”