This post describes key concepts considering disaster recovery of IT services. As an example I will use recovery of SharePoint service, since it is what I am working with mostly, but most of concepts are applicable for any IT services.
You probably hear a lot about backups and recovery but do you have disaster recovery plan? In my experience less than 10% of customers have it. I don't mean they don't have backups, they do. But do they really know how to restore the service using those backups? Did they create detailed step by step instructions on how to do that? Do they test those instructions regularly? Well, as I said, the answer is NO in 90% of cases.