Version:  Odoo 9

Issue:  Case and Piece conversion and adding/deducting of available quantity

Our company needs to monitor case and piece conversion for a single item.  Whereas, we receive items from supplier by case or piece;  & also sell our items in case or piece.  Thus, for example,

RECEIVING example:

Tissue Roll 2ply by 4 can be received as 3cases and 5 pieces (12 pieces per case).  

The total inventory received should be (3 x 12 = 36pcs + 5pcs = 41pcs total inventory for a single item)

SELLING example:

Customer orders Tissue Roll 2ply by 4 in 1case and 6pieces; thus, (1 case = 12 pcs + 6 pcs = 18pcs total qty ordered or 1case and 6pcs)

Available inventory should then become 23 pieces or in the system it should be viewed as 1case and 9pcs.

How can we do this in Odoo 9 please?  Is it even possible?

Any help is greatly appreciated.  Thank you.