Dear Bhanu,
Sorry that i left your query unnoticed since i had closed the issue and never made a come back to it.
If it is still not try this,
PM&CS-->Master data in PM & CS-->Tech: objects-->Equipment-->Equipment categories-->Maintain equipment category:- Select your equipment category for fleet and check the box ""Linear"".
Even though it has no functional relationship with PAM, interestingly it worked out. 
If you have further queries please let me know,
VINOD.V