Online Patching feature of Oracle E-Business Suites 12.2.x allows patching activity, while users are working on the System. The Online Patching cycle consists of several phases (i.e prepare, apply, finalize, cutover and cleanup etc.), with the critical phase where the changes are committed being called cutover. Up to this phase, you can run a special phase called abort, which will undo the changes made so far in the patching cycle.
System can be rolled back, If cutover fails or after cutover, you want to revert to the state of the system before the patching cycle was started. Here, you can see the advantage of Oracle Database Flashback feature to go back to a designated point in time (a restore point). You should create the restore point just before running the cutover phase.
In order to proceed further, one may use the following Oracle Document, from where abstract was taken:
Oracle E-Business Suite Release 12.2: Backup and Recovery Guidelines For Online Patching Cutover (Doc ID 1584097.1)