...With pkg_version-zypper.rb script you can first see a nice list of package statuses and ignore packages' minor versions (eg. from version 1.2.3-1.2 to 1.2.3-1.3) when upgrading your software.
In daily usage basis, this enables to avoid re-installing tens and tens of programs for no big reason (usually) and do it only when programs in repository has been updated.
NB! It is not an official recommendation to do so as packages have their version number for a reason!
I personally have been ignoring RPM versions for years and have not been into any trouble because of that.
Usually you'd want to use the script as: sudo ./pkg_version-zypper.rb -f '<' -r -u
But you can also take package versions into account: sudo ....