Hi Abhishek,
Just to be sure; have you check that all the customizing for the actions is the same in DEV, QA and PROD. Maybe something was forgotten to be transported to PROD. Transaction SCU0 can be used to easily compare customizing across System.
If the customizing is the same I guess your best bet is debugging. How did you implement the conditions of the actions? If you implemented them using custom code in the respective BAdIs you should be able to simply set break points in this methods. Otherwise, if you use WF-conditions it is a little more complicated. In this case I'd start debugging in the function module CRM_ACTION_DETERMINE.
Christian