inoperable time; downtime
Technical computing term referring to the period during which a system, component, or service is not functioning or unavailable.
We need to minimize the server's inoperable time.
このシステムの動作不能時間は年間数時間に過ぎない。
This system's downtime is only a few hours per year.
Compound of 動作 (operation) + 不能 (inability) + 時間 (time). A straightforward technical term with no special historical derivation.