If a SOC has a goal of 99.999% uptime, approximately how many minutes of downtime per year is considered within its goal?

If a SOC has a goal of 99.999% uptime, approximately how many minutes of downtime per year is considered within its goal?

• A. Approximately 1 hour per year.
• B. Approximately 5 hours per year.
• C. Approximately 1 day per year.
• D. Approximately 5 minutes per year.

Answer: (D)

Five nines of availability means only about 0.00001 of the time can be down. In a year, there are 365 days × 24 hours × 60 minutes = 525,600 minutes. Downtime allowed = 525,600 × 0.00001 = 5.256 minutes. So the approximate downtime within the goal is about 5 minutes per year. This level of reliability is extremely high, which is why it’s described as five nines.

Five nines of availability means only about 0.00001 of the time can be down. In a year, there are 365 days × 24 hours × 60 minutes = 525,600 minutes. Downtime allowed = 525,600 × 0.00001 = 5.256 minutes. So the approximate downtime within the goal is about 5 minutes per year. This level of reliability is extremely high, which is why it’s described as five nines.