基于组合模型的软件可靠性预计方法

为了提高软件可靠性预计精度和稳定性，本文提出基于组合模型的软件可靠性预计方法。构建组合模型的过程包括选取基模型和确定各基模型的权值。选取基模型时依据的准则有生命周期阶段、模型用户需求、故障数据类型、故障趋势匹配、模型假设吻合和模型预计偏好，并在此基础上阐述了基模型选取算法。基模型权值的确定采用序列似然比方法。最后，引用一组软件故障数据，用于检验此组合模型的预计效果。通过与单个模型的对比，显示组合模型预计结果更为可信。

Software reliability prediction based on combination model

In order to improve the accuracy and stability of software reliability prediction, a method of software reliability prediction based on combination model is proposed. To build a combination model, several suitable component models should be selected, and every component model should be assigned an appropriate weight. Several criteria should be followed to select component models, which are life cycle phase, demand of model user, type of fault data, similarity of fault trend, fit of model assumptions and bias of model prediction, and an algorithm for selecting component model is gave. The sequence likelihood ratio is used to determine the weight of component model. Finally, a group of software fault data is used to check the prediction quality of the combination model. Compared with a single model, the result of the combination model is more credible.