He does your basic backup imaging(I think he uses Macrium.) But periodically he puts an internal drive that is identical make/model/size to the system drive in his PC, in a docking station and restores the image of his working system to that drive. He stores the drive away. Now if he has a drive failure he opens the box, replaces the HD, and boots to a working system.
Of course if there's nothing wrong with the boot drive physically, then he just does an image restore from the drive in the dock, booting the Macrium rescue disk from USB or whatever.-MilesAhead
FWIW, I do the same thing, also with Macrium Reflect. Luckily, on my main box I have a twin-bay drive caddy with two SSDs, so its a piece of cake to do this. That caddy is one of the most convenient items I've ever had on a computer.
I used to use Rollback RX when on XP but even the latest versions of it hose my W7 and W8 systems.
I have yet to see Macrium fail. For example, I just restored a four-drive system to Win7 from Win8.
Having a clone of the boot drive is useful but I tend to forget to keep it up to date, whereas I do remember to carry out regular backups, rotating the backup media (I know that's illogical).