“…While the LUtype RG-factorization is a key technique for calculating the transient performance measures such as the first passage time, the waiting-time and the sojourn time. In this connection, readers are referred to Li et al [22], Wang et al [38], Jiang and Liu [20], Zhang and Hou [40], Avram and Chedom [6], Gao and Liu [14], and Yu and Alfa [39], who have used the RG-factorization.…”