When creating an Purchase Order after choosing an supplier, It would be logical that when I add an PO line item, I can only choose Products that are assigned to the supplier.
As things are right now i get the total list of available items which could allow me to add items that the supplier does not even have in it's assortment. Also it would reduce the number of errors.
Thnaks in advance!
There is an option to Limit product search by products linked to selected supplier.
Go to General Settings and scroll down to Purchase process customisation to turn this on.
I hope this helps!
Here is the option on the General Settings page mentioned by Ian.