一种开放环境下的软件可靠性评估方法

An Approach of Software Reliability Evaluation in the Open Environment

目前,软件系统运行环境日益增强的开放性对原有的软件开发技术(包括软件可靠性评估方法)提出了挑战.一些基于软件测试和模拟的方法由于效率上的不足而不再适用;而另一些方法,例如基于状态的可靠性评估方法,虽然在效率上有了很大的提高,但在适用范围上又存在着不足,比如不能很好地处理含并行结构的系统.为此,在基于状态的可靠性评估方法的基础上,文中提出一种改进的可靠性评估方法,以兼顾效率和适用范围两个方面.首先介绍如何用Petri网来描述各种复杂结构的系统,接着介绍一种自底向上的可靠性计算过程,该过程能对并行结构进行分解和综合计算,高效、准确地计算出系统的可靠性.该方法还可以估算出组件对系统的重要性,从而大大地增强了可靠性评估在软件开发中的作用.

Nowadays software environment has been more and more open than before,the openness of environment has greatly influenced many existing software development techniques,including software reliability evaluation.Due to the weakness in efficiency,methods based on testing or simulations are not competent in the open environment;other methods,such as the state-based methods,are more efficient,but are unable to deal with the systems with concurrency.So this paper tries to put forward an improved reliability evaluation method which can do better in both efficiency and applicability.This method first describes how to use Petri nets as software architecture description;and then introduces a bottom-up way to calculate the system＇s reliability,the calculation process can be done efficiently and accurately,and can also deal with systems with concurrency,which can hardly be handled by existing methods;the method can also generate information reflecting the component＇s importance to the whole system,which can make software reliability evaluation play a more important role in software development.