FAQ : What is the Service Availability of Office365?

A common question I get is around what our service availability is and about how we handle any planned or unplanned outages.  We have a strong commitment to fulfilling our uptime guaranteer and constantly improving both the service and our communications channels about service availability, and this is why we have a financially backed SLA.  Check out this blog post for more information https://community.office365.com/en-us/b/office_365_technical_blog/archive/2011/11/07/service-availability-in-office-365.aspx