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Myth of the Nines Monthly Times

High availability is a characteristic of a system, which aims to ensure an agreed level of operational performance, usually uptime, for a higher-than-normal period. The nines is a measure of this availability, the ratio of uptime to the sum of uptime and downtime, typically expressed as a percentage, such as 99.95%.

The monthly downtime equals 1 minus the availability times one month.

Formula

QuantityVariable["MDT", "Time"] == Quantity[1, "Months"]*(1 - QuantityVariable["A", "Unitless"])

symbol description physical quantity
MDT monthly downtime "Time"
A availability "Unitless"

Forms

Examples

Get the resource:

In[1]:=
ResourceObject["Myth of the Nines Monthly Times"]
Out[1]=

Get the formula:

In[2]:=
FormulaData[ResourceObject["Myth of the Nines Monthly Times"]]
Out[2]=

Use some values:

In[3]:=
FormulaData[
 ResourceObject[
  "Myth of the Nines Monthly Times"], {QuantityVariable[
   "A","Unitless"] -> 0.99`}]
Out[3]=

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