Availability vs. Disponibility

By Jaxson

  • Availability

    In reliability theory and reliability engineering, the term availability has the following meanings:

    The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e. a random, time. Simply put, availability is the proportion of time a system is in a functioning condition. This is often described as a mission capable rate. Mathematically, this is expressed as 100% minus unavailability.

    The ratio of (a) the total time a functional unit is capable of being used during a given interval to (b) the length of the interval.

    For example, a unit that is capable of being used 100 hours per week (168 hours) would have an availability of 100/168. However, typical availability values are specified in decimal (such as 0.9998). In high availability applications, a metric known as nines, corresponding to the number of nines following the decimal point, is used. With this convention, “five nines” equals 0.99999 (or 99.999%) availability.

  • Availability (noun)

    The quality of being available.

    “What is your availability this week?”

  • Availability (noun)

    That which is available.

    “We have several availabilities.”

  • Disponibility (noun)


  • Availability (noun)

    the quality of being able to be used or obtained

    “turkey producers had been losing sales because of the all-year-round availability of beef”

    “the availability of social housing varies widely in rural areas”

  • Availability (noun)

    the state of being otherwise unoccupied; freedom to do something

    “they enquired as to my availability for a game the following evening”

  • Availability (noun)

    the state of not being currently involved in a sexual or romantic relationship

    “if you call yourself ‘Miss’ you’re advertising your availability to any man who takes a fancy”

Oxford Dictionary

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