Syncronization between SO and PO in Back to Back Process

Hello,

Currently, we are in R12.1.2 and we want a Synchronization between Sales order and Purchase order in Back to Back Process. In that we want functionality like, if we update the quantity on sale order line or cancel the sales order line then it will update the quantity of purchase requisition and if we update the PO quantity or cancel the Purchase order then Sales order order quantity should be updated like vice versa.

So,How can we achieve the Sync functionality of SO and PO in B2C Process ? Is there any setup for that ?

Thanks,

Rahul Modi.