OPP: Actual 24, Target 2

From the Administer Concurrent Managers form, I see Output Post Processor has 24 Active, but 2 Target. System Admin says that 2 of the OPP processes use high memory on OS level.

So, EBS keeps starting new OPP processes, even the target is set to 2.  I see there are 24 FNDOPP processes on OS.

What is the best way to fix this without bouncing the Concurrent Manager, because this is a production environment? How can I prevent this behavior from happening again?

Thank you.