When is the preference purchase rule automatically determined?

The preference rule is redefined when a purchase mutation occurs if the purchase was not orderable in the old situation but is in the new situation. It is also redefined if the purchase was expired in the old situation but not in the new situation. The automatic determination only occurs when modifying a purchase data.

When creating a purchase, it can be indicated directly whether the new purchase line is a preference rule, and by doing so, the existing preference of an existing purchase line from the same supplier is removed.