You may automate the updates of security patches (14.4-p5 -> 14.4-p6) pretty simple.
Just add the commands you would type manually in the shell into a shell script. Then, like it's described in the HB, or as
Charlie_ pointed out, under TIPS in the man page, run a cron job that executes that script, when new patches are available.
But I don't think upgrades to minor versions (14.3 -> 14.4) and particulary not major version (14 -> 15) to be fully automated were a good idea, since there are often some changes, so things you need to decide and do manually yourself.
If you would run that fully automated, just checking it all off unchecked by yourself, you can produce a mess. And then first you need to figure out, what exactly had happen, before you can even start the cleaning up.
IMO produces way more trouble than it seems saving you time at the first glance.
