// Simply converts the failure rate to a MTBF number, without any string formatting
public static double FailureRateToMTBF(double failureRate, MTBFUnits units)
{
failureRate = Math.Max(failureRate, MIN_FAILURE_RATE);
double mtbfSeconds = 1.0f / failureRate;
switch (units)
{
case MTBFUnits.SECONDS:
return(mtbfSeconds);
case MTBFUnits.MINUTES:
return(mtbfSeconds / 60);
case MTBFUnits.HOURS:
return(mtbfSeconds / 60 / 60);
case MTBFUnits.DAYS:
return(mtbfSeconds / 60 / 60 / 24);
case MTBFUnits.YEARS:
return(mtbfSeconds / 60 / 60 / 24 / 365);
default:
return(mtbfSeconds);
}
}
public static void FailureRateToMTBFString(double failureRate, MTBFUnits units, bool shortForm,
int maximum, out string output)
{
var currentUnit = (int)MTBFUnits.SECONDS;
var mtbf = FailureRateToMTBF(failureRate, (MTBFUnits)currentUnit);
while (mtbf > maximum)
{
currentUnit++;
mtbf = FailureRateToMTBF(failureRate, (MTBFUnits)currentUnit);
if ((MTBFUnits)currentUnit == MTBFUnits.INVALID)
{
break;
}
}
if (shortForm)
{
output = string.Format("{0:F2}{1}", mtbf,
UnitStringForMTBFUnitShort((MTBFUnits)currentUnit)).ToString();
}
else
{
output = string.Format("{0:F2}{1}", mtbf,
UnitStringForMTBFUnit((MTBFUnits)currentUnit)).ToString();
}
}
internal static string UnitStringForMTBFUnitShort(MTBFUnits units)
{
switch (units)
{
case MTBFUnits.SECONDS:
return("s");
case MTBFUnits.MINUTES:
return("m");
case MTBFUnits.HOURS:
return("h");
case MTBFUnits.DAYS:
return("d");
case MTBFUnits.YEARS:
return("y");
default:
return("-");
}
}
internal static string UnitStringForMTBFUnit(MTBFUnits units)
{
switch (units)
{
case MTBFUnits.SECONDS:
return("seconds");
case MTBFUnits.MINUTES:
return("minutes");
case MTBFUnits.HOURS:
return("hours");
case MTBFUnits.DAYS:
return("days");
case MTBFUnits.YEARS:
return("years");
default:
return("invalid");
}
}
