No software CD s included in new MacBook Pro package unlike earlier editions. Is there a way of backing up of O/S or how to install the O/S in case need of formatting the computer?
You just need a WiFi point - your computer has the ability to download and install the OS as required (such as after installing a new drive). There is also a recovery partition, as mentioned above (its less useful if the drive has failed) and then, you can create an external recovery drive, but this is slightly more complicated.
Sounds serious to me; most people upgrading their MacBook Pro now would probably be changing from a Snow Leopard or earlier era system.
As for the actual question, with the current Mavericks OS you can either use recovery, or download from the App Store and use the createinstallmedia tool to make a flash drive.