MRP and serial numbers

If I have understood well the serial numbers in Dolibarr, I can see that I can create/add a SN only on expedition.
But if I have a product and in its definition I set that there is a Serial Number, if this product is a “built” product (i.e. a one for which I have a BOM and a Production order), when I set o production order that is not created because I have not assigned a serial number. By the way I see the column for the serial number in the product list for the production order, but I cannot insert or change any data there.
Pls where am i wrong?
thanx all

Hello Gio,

Usually the way it works is that you assign a SN when you finish a manufacturing order (MO) . This is happening so you can track when the product with the specific SN was built and which raw material it used to be built. Thats useful for tracebility that is required for QC. So in my opinion is the expected behavior.
Are you trying to produce customer specific products or standard products?

Hi elsp,
I defined a final product has having a SN, but if I create a production order with it, simply I cannot going on with the production (my production confirmation on stopped), due to the SN (not assigned yet), and I cannot assign o change any value in the MRP production form. So I am confused.
My production is a way in the middle, i.e. I have a small production of things that are low in numbers (think of 5 to 10 pieces) that could change a little from lot to lot.
I will try to apply your suggestion that implies, if I am not wrong, that I define a product without SN, then I produce it and after I change it again adding a serial number for the expedition.
However I am not so sure I can handle it while in production. I will try on my next lot (unfortunately not too soon). Now I will try with a fake production to see what is possible.