中文摘要：

主要解决设备故障停机时间较长情况下如何修正基本检查模型并优化维修间隔期的决策问题。首先阐述了时间延迟概念及其原理，建立了基于时间延迟维修理论的单元件系统基本检查模型，该基本检查模型的建立是基于设备故障停机时间相对检查周期较短的情况，提出了缺陷在故障停机期间继续发生的假定条件，该假定条件并不适合故障停机时间较长的情况，为此提出了只有在设备运行期间才会发生缺陷的假定条件并修正了基本检查模型，根据修正后的检查模型估算出检查周期内故障次数期望值。通过案例比较基本检查模型与修正模型之间的差异，计算结果表明，修正后的模型在检查周期的确定、故障停机时间期望值的计算方面具有更高的精度。

英文摘要：

This paper is mainly concerned on problems of revising the basic inspection model and optimizing the preventive maintenance interval of equipment in the case of longer failure downtime. Firstly, the concept of delay time and its maintenance theory are introduced, therefore, a basic inspection model for single-unit system is established using delay time maintenance theory. In modeling this inspection model, it is based on the case that failure downtime is short compared to inspection cycle. Therefore, assuming that defects continue to arise during failure downtime. Obviously, this assumption is not suit for the case that failure downtime is not sufficiently small. So this paper assumes that defects only occurred in operation time of equipment. Then the basic inspection model is revised, and the expected number of failures over inspection cycle is given by the revised inspection model. Finally, a case study is also proposed to highlight the differences. The revised downtime model is a more sensitive model in determining the actual downtime and optimal inspection interval.