This was such a a small thing and I only found it very recently. Basically, when you tick an inforecord as regular vendor, even if you have multiple inforecord for the same material code, in ME57, you will not get a list of inforecords to select from. Purchasing requisitions are automatically allocated to the inforecord with the “Regular Vendor” tick. This can save significant amount of time for the person who is handling purchasing. This also will increase accuracy of the assigning process significantly.
In case if you want to assign a particular purchasing requisition to a vendor other than the regular vendor, you can use the “manual assignment” functionality in ME57.
You have to enable this functionality by plant in the config. Below is the process.
Select Plant for the Regular Vendor Setting
Before Selecting Regular Vendor A List Will be displayed with all the possible options. User will have to select by double clicking on the desired vendor
Selecting Regular Vendor In Info Record
After Selecting One InfoRecord as “Regular Vendor”, user no longer gets the list, although they have multiple inforecords. Purchase Requisitions are automatically allocated when “Assign Automatically” is selected.