[donrhummy]

No, it would allow them 131 hours of downtime in 15 years: ( 365 days * 24 hours/day * 15 yrs ) * .001 = 131.4

[DougWebb]

99.999% uptime == 0.001% downtime 0.001% is a factor of 0.00001, not 0.001. Remember, % means 1/100th.