多层缺陷关联效应对软件可靠性增长过程的影响

Impacts of Correlation Effects among Multi-layer Faults on Software Reliability Growth Processes

软件系统中的缺陷通常以非常复杂的方式互相关联,并最终导致系统失效。基于非齐次泊松过程的软件可靠性增长模型,是一种描述软件随机失效行为和测量软件可靠性增长过程的常见工具。为此,考虑到有关联作用的多层缺陷,提出一个基于非齐次泊松过程的软件可靠性增长模型来研究软件系统的可靠性增长过程,并通过现实数据集对模型的性能进行评估。研究表明,新模型抓住了多层缺陷的关联效应,很好地拟合了缺陷数据集,且优于传统模型。此外,对于同时考虑了可靠性要求和测试成本的软件发行策略,研究发现,如果测试团队忽略缺陷不同层之间的关联效应,会使软件包发行到市场的最佳时间提前,从而相应的增加整体成本。

Faults in the software systems,which eventually cause the system failures,are usually connected with each other in complicated ways.Software reliability growth models based on non-homogeneous Poisson processes are widely adopted tools when describing the stochastic failure behavior and measuring the reliability growth in software systems.Considering agroup of correlated faults,a new model was built to examine the reliability of software systems and assess the model＇s performance from real-world data sets.Numerical studies show that the new model captures correlation effects among multi-layer faults,fits the failure data well and performs better than traditional models.The optimal software release policy,which considers both the reliability requirement and the software testing cost,was also formally studied.It is found that if the correlation effects among different layers of faults are ignored by the software testing team,the best time to release the software package to the market will be much earlier while the overall cost will be much higher.