Resolution:
In the BPM log files, messages similar to the following warning message is seen.

03 Apr 2013 05:00:08,086 [PVM:DB Work Queue] [WARN ] com.tibco.pvm.system.PvmSystem - Module[365] not ready, rescheduling event for ProcessQueue[id:7232] with lower priority


Resolution:
==========
These warning messages indicate that an event has been received on a module, which is not in a ready state. The module could be in either a stopped or not deployed state. Start or deploy the application from Administrator for the process engine to start executing these pending events. If you are unable to start these applications, contact TIBCO Support.