Concurrent Programs Business Events

In R12 for concurrent programs submission and completion has business events associated with them
in the concurrent program definition form there is a business events tab which displays the list of events associated

Here you specify the points at which business events are enabled. The possible points are:
Request Submitted
Request On Hold
Request Resumed
Request Running
Program Completed
Post Processing Started
Post Processing Ended
Request Completed

But make sure you set the profile "Concurrent: Business Intelligence Integration Enable". You will need to Set "Yes" to enable Business Events from Concurrent Processing System

After this you create a susbcription for this and can launch the required custom action either a work flow launch or plsql code exectuion