Two-phases service system with unreliable devices / *I. V. Rudenko.* // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2012. № 4. P. 8-14
[Moscow Univ. Math. Bulletin. Vol. 72, N 2, 2017. P. 0].

A two-phase queueing system with a finite number of places in the buffer between the phases and unreliable servers is considered. It is shown that the queueing system can be interpreted as a queue functioning in a random environment. The ergodicity condition is found. The asymptotics of the traffic coefficient is obtained for the exponential case.

*Key words*:
multiphase queueing systems, ergodicity condition, traffic coefficient.