In this paper,two-computer redundant system s Non-Morkov process model is converted to Morkov process model using supplementary variable, then the formula for reliability is deduced.

• 应用补充变量,将双机冗余系统的非马尔可夫过程模型转化为马尔可夫过程模型,并推导出了可靠性及有效性公式。