As a subscriber trusting your business critical application with an Online Services provider, you are of course demanding assurance and accountability in the form of Service Level Agreements (SLAs).
The "Service Level Agreement for Microsoft Online Services" covers the following services:
We provide financial backing to our commitment to achieve and maintain the Service Levels for our Services. If we do not achieve and maintain the Service Levels for each Service as described in our SLA, then you may be eligible for a credit towards a portion of your monthly service fees.
We calculate the “Monthly Uptime Percentage” for a Service by the following formula:
100 * (x-y) / x
where x = "Total number of minutes in a month" and y = "Downtime"
If the Monthly Uptime Percentage falls below 99.9% for any given month, you may be eligible for the following Service Credit:
Some of our friends in the market take a different view of downtime, and others offers no standard service level agreement.