Gun, LeventMakowski, Armand M.This paper presents a class of Quasi-Birth-and-Death processes with finite state space for which the invariant probability vector is found to admit a matrix-geometric representation. The corresponding rate matrix is given explicitly in terms of the model parameters, and the resulting closed-form expression is proposed as a basis for efficient calculation of the invariant probability vector. The framework presented in this paper provides a unified approach to the study of several well-known queueing system.en-USTechnical Report