Patch policies were introduced in the ZENworks 11 SP3 release with the intent to eventually replace the Mandatory Baseline functionality. Mandatory baselines can be used to deploy a base set of specific patches to a group of devices. Patch policies provide the same capability (deploying specific patches), but add the flexibility to deploy patches via rules as well, ensuring that devices continually receive any new patches that meet the rule criteria.
The transition period has come to an end, and we are removing mandatory baselines from the ZENworks 2017 release. If you are still using mandatory baselines, ZENworks 2017 will convert your baselines into Patch policies. One of our Patch Management engineers, Navdeep Grover, put together the following video to show you the conversion process: