Hi Sethuraman,
What happened when you release the third production order? Please release the third order and check.
Also check the any production scheduling profile is assigned to work scheduling view. If yes then check the production scheduling profile in OPKP for Confirm available partial quantity.
In OPJK for business function 1 - material availability check during order creation check the setting for No Check and Check availability while saving.
Also check OSS note 1043022 - Availability check: No indication of missing parts if valid for your version.
Regards,
R.Brahmankar