The type of business obviously has a significant role .. in my case I work within the mortgage lending industry and not being there means no business, e.g. customers just go somewhere else. Our DR plan attempted to get systems back up and running in a new office and location within a few hours and accepting business. OK so it was never tested in anger, but the test was pretty nerve racking AND you need to test to discover the holes .. otherwise when you do need it, it doesn't work .. just like the best disaster movies.