Queueing network models of re-entrant lines are developed, and are converted to the canonical forms that are solvable by no n-linear matrix equations.Irreducibility of such systems is studied.

• 将开环可重入生产系统的模型化成非线性矩阵方程可解的形式，在此基础上研究系统在随机调度策略下的不可约性。