平均停机间隔时间（MTBO）指标提供了归因于设备供应商的所有电信网元故障（硬件和软件）的频率，包括影响短期停机的客户。相比之下，传统的平均无故障时间（MTBF）指标仅针对导致元件更换的总故障。MTBO指标已被QuEST Forum/TL9000组织接受为关键行业指标。

The Mean Time Between Outages (MTBO) metric provides the frequency of all telecommunications network element failures (hardware and software) attributed to equipment supplier - including customer impacting short duration outages. By contrast, the traditional Mean Time Between Failure (MTBF) metric only addresses total failures that lead to element replacement. The MTBO metric has been accepted as a key industry metric by the QuEST Forum/TL9000 organization.