When a production order is generated from a sale order (from the "Planning" button"), all lines from this sale order are taken into account to create production orders.
In many cases, the user just want to create a production order for a specific line and a specific quantity.

I would be very helpful to have the possibility, from the page "Sales Order Planning" (99000883), to choose lines we want to use for the production order creation process, and the quantity we want to produce on each line.