Dear Nag Krish,
What you have said below is correct way and follow this process.
in SAP ECC, we can create Production order without Material(do it with material and as per standard SAP, fetch it's present BOM and Routing) and components can be added with -ve qty which we are going to receive into Stock and main Product will be added as +ve qty in Component overview, So main product gets consumed and Child parts are going to stock by 531 mvt type.
But problem is created because SAP ME shop floor execution system is not accepting the same.
Actually, I have worked on such scenario and my suggestion is to proceed with material. i.e. create order with material then do the GI to order and order confirmation wherein you can book the labor time etc. but only need to care that, do not perform goods receipt for order which you can avoid by manually entering the last operation control key as PP01 rather than PP03.
After words, Technically complete the order without doing GR for production order.
In this process the components which comes back in stock are strictly comes with the current price.
Rest of steps like settlement and production order closure can be done as usual.
Try this on DEV server and come back with your results.
Regards,
Narresh