中文摘要：

可靠性、维修性和可用性是描述复杂装置质量属性的三个重要指标。在某大型装置的现场故障和维修数据的经验分析基础上，运用分段线性模型确定了装置可靠性改进趋势。针对装置现场故障和维修数据的小样本问题，给出了装置现场可靠性和维修性的贝叶斯模型，并用WinBUGS软件对其进行了求解计算。继而分析给出了装置可用性最恰当描述——任务可用度的闭合表达形式。最后，通过与极大似然法进行对比，发现应用贝叶斯方法分析该大型装置现场可靠性更有效。

英文摘要：

Reliability, maintainability and availability are three important attributes to describe the qualityof a large-scale device. A certain large-scale device is in the prototype testing phase and clearly exhibits re-liability growth. However, the high environmental stress and operation cost result in the difficulties to col-lect field data. Moreover, the downtime constraint should be considered when the availability anays1s 1Scarried out. Therefore, it is very difficult to carry out device reliability, maintainability and availability as-sessments. In this paper, the empirical analysis is first carried out based on the field failure and mainte-nance data, then the device reliability improvement trend is determined with a piecewise linear model. Forthe small sample question of the field failure and maintenance data, the Bayesian method is introduced, andthe field reliability and maintainability parameters are calculated by the soft WinBUGS. Then the most ap-propriate description of the system availability--mission availability with closed expression form is presen-ted. In order to illustrate the effectiveness of the method, the field data from June 4, 2007 to May 17,2010 has been couected. Through the case study, two reliability change-points are determined and thus thedevice reliability and maintainability are analyzed with Bayesian method. As a result, the average relativeerror of Bayesian and maximum likelihood methods are 0.42% and 8.78% respectively. Then it can beconcluded that using the Bayesian method to carry out field reliability analysis is more effective comparedto the maximum likelihood method.