随着人们对计算机网络系统的依赖性的不断增强,网络系统的可信赖性研究变得越来越重要.本文首先对可信赖性的概念及其主要性能指标进行论述,并对系统可信赖性各种模型方法及求解特点作了分类比较.在此基础上研究了随机Petri网(SPN)对网络系统可信赖性建模分析的方法和步骤,着重研究了随机Petri网描述系统的服务失效模型和容错模型,并给出了网络系统可信赖性分析中主要指标的计算方法.最后对于应用随机Petri方法分析网络系统可信赖性时存在的问题以及研究现状作了分析和总结,并对今后研究的方向进行了展望.

With people rely more on computer networks,the study on the dependability of networks is increasingly significant.First the paper provides insight about the main definitions and attributes related to dependability,and classifies and compares the general models for dependability.On the basis of the synthesis,the modeling and analysis methods using Stochastic Petri Net (SPN) for the network system dependability are mainly investigated.The service failure and fault tolerance SPN models and the calculating methods of main dependability attributes are examined.The existing problems and applications of SPN are concluded that concern the dependability of networks. And directions for future research are also indicated.