Several settings, where the notion of virtual age is employed, are discussed. We argue that the age reduction imperfect repair modeling is often not sufficiently justified in practice, as it is not possible to execute repair in most of real situations that conforms with this model. On the other hand, a shock‐based virtual age model is suggested and justified via the probabilities of failures on shocks. The new notion of virtual age for degrading items is also introduced. We discuss how to recalculate virtual age after switching from one regime to another. Several examples illustrating different notions of virtual age are presented.

中文翻译：

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虚拟时代，是真的吗？- 在可靠性背景下讨论虚拟时代

讨论了使用虚拟年龄概念的几种设置。我们认为，减龄不完美修复建模在实践中往往不够合理，因为在大多数符合该模型的实际情况下不可能执行修复。另一方面，基于冲击的虚拟年龄模型被建议并通过冲击失败的概率来证明。还引入了用于降解物品的虚拟年龄的新概念。我们讨论了从一种制度切换到另一种制度后如何重新计算虚拟年龄。展示了说明虚拟年龄的不同概念的几个示例。