According to this question

[Does Apple's Time Machine app really copy everthing](https://superuser.com/questions/71824/does-apples-time-machine-app-really-copy-everthing) 

Time Machine can do a **full system** restore as long as you have the original OS dvd.

With this in mind, is there any point to doing a full system backup ([see here](https://superuser.com/questions/375/backup-software-for-mac-os-x/510#510)) using other software?

Why not just use Time Machine? It seems to cover System and Data backups no?

**UPDATE:**

so far the answers have been about redundancy, and replication... which are excellent points.

But I'm asking about tool and strategies. I'm assuming once I backup using time machine or any tool, then I can replicated and off site that backup independently right?