Vendors: Validity Periods in a Vendor Hierarchy 
Vendors: Validity Periods in a Vendor Hierarchy
Use
A validity period consists of a valid-from date and a valid-to date. By specifying validity periods for hierarchy nodes, you can take account of the fact that vendor hierarchies usually change over time.
The corporate structure of a vendor may change and you may want to restructure the vendor hierarchy in advance. Alternatively, sales through some retail outlets in a vendor hierarchy may develop substantially faster than through others, requiring that you reassign the top-selling stores within the hierarchy.