The new reliability notion describing the remaining lifetime is introduced for items with monotonically increasing degradation. We consider the remaining lifetime of an item (to be called, the predicted remaining lifetime) after its degradation reaches the predetermined level. The prediction is executed at inception of an item into operation. For the nonhomogeneous stochastic processes of degradation, this characteristic depends on the random first passage time of a degradation process. Some properties of the predicted remaining lifetime and the corresponding stochastic comparisons are discussed for items from homogeneous and heterogeneous populations, and a generalization to the case of the n-component coherent system is outlined. The problem of regime switching is described, and the new notion of the corresponding virtual age after the switching is proposed.

描述剩余寿命的新可靠性概念被引入用于具有单调递增退化的项目。我们考虑物品在退化达到预定水平后的剩余寿命（称为预测剩余寿命）。预测在项目开始运行时执行。对于非均匀随机退化过程，该特性取决于退化过程的随机第一次通过时间。讨论了来自同质和异质种群的项目的预测剩余寿命的一些属性和相应的随机比较，并推广到n的情况概述了组件相干系统。描述了制度切换问题，提出了切换后对应虚拟年龄的新概念。