Availability, Recovery Time Objective (RTO)
and Recovery Point Objective (RPO)

Business continuance and disaster recovery corporate objectives should be based on the following criteria:

Availability is defined with five classes as:

• mission critical where the server or data must be available 99.999% of the time - the "five-nines" level of protection equates to 5 minutes downtime per year
• business vital is 99.99% availability = 53 minutes downtime per year
• mission important is 99.9% or 9 hours per year
• data important is 99% or 3.6 days per year
• data not important is 90% or 36 days per year

Recovery Time Objective (RTO) is defined as the maximum time allowable for recovering data:

• mission critical data the RTO (taken as .00001 of the total year) is 1.5 minutes
• business vital data the RTO is 15 minutes
• mission important data the RTO is two hours
• data important for productivity the RTO is one day
• data not important to operation the RTO is one week

Recovery Point Objective (RPO) is how much work in progress that can be lost:

• Tier 0 - No off-site data
• Tier 1 - Data backup with no Hot Site
• Tier 2 - Data backup with a Hot Site
• Tier 3 - Electronic vaulting
• Tier 4 - Point-in-time copies
• Tier 5 - Transaction integrity
• Tier 6 - Zero or little data loss
• Tier 7 - Highly automated, business-integrated solution