===== Downtime =====
[[dido:public:ra:xapend:xapend.a_glossary:start| Return to Glossary ]]

**Downtime (T<sub>d</sub>)** is the Mission Duration times the sum of all of the different kinds of time required to transition from being down to the time to be fully operational divided by the [[dido:public:ra:xapend:xapend.a_glossary:m:mbtf]].

  * [[dido:public:ra:xapend:xapend.a_glossary:m:mttr]] is time required to restore operations the level defined in the system specification
  * [[dido:public:ra:xapend:xapend.a_glossary:m:mldt]] is time required to obtain parts from the part depot or from the manufacturer including transportation to the site
  * [[dido:public:ra:xapend:xapend.a_glossary:m:mamdt]] is average time required to perform diagnostics and replace parts 

Source: [[https://en.wikipedia.org/wiki/Availability_(system) | Downtime ]]