容错系统不仅会产生硬件故障，由于连续长时间的运行，系统的性能也会逐渐下降或失效，即老化现象。综合考虑容错系统中的硬件故障和老化现象，提出了将传统的冗余技术和软件抗衰技术相结合的策略，并给出了该系统的非马尔可夫随机Petri网模型，随之对基于该模型的系统进行了定量分析。

A fault-tolerant system experiences a crash due to hardware components' faults or progressive performance degradation as an "aging"  phenomenon,  because of running continuously for very long periods.  This paper considers both hardware components' faults and "aging"  phenomenon, proposes composing redundant structure and rejuvenation schedule in the fault-tolerant system, formalizes the system with Non-Markovian stochastic Petri nets,  and evaluates quantitatively the performance of a system based on this model.