可重入生产系统的QBD型模型

QUASI-BIRTH-AND-DEATH TYPE MODELS OF REENTRANT LINES

考虑可重入生产系统除第一个外均为有限缓冲区的情形 ,建立了两种两站四缓冲区的拟生灭过程 ( QBD)型模型 .系统在随机调度策略下状态集是不可约的 ,而在最后一个缓冲区先加工 ( LBFS)的策略下状态集是可约的 .将可约的状态集化成不可约的吸收集和可约状态集的和 .求出了系统状态的稳态分布 。

Quasi birth and death(QBD) models of two kinds of reentrant lines are developed with two stations and four buffers for cases where all but the first buffer capacities are assumed to be finite. The systems are irreducible under random scheduling and reducible under last buffer first serve(LBFS) scheduling policy. The reducible set of states is split into irreducible absorbing subset and reducible subset. Steady state distributions are obtained. The sufficient and necessary conditions of stability are given.