In addition to the Default Supplier option dropship360 provides you with another guard against backorder issues. The Inventory Buffer is an optional configuration designed to help decrease the likelihood of selling a product no longer in stock. When enabled (by inserting a number into the Buffer field) the amount will automatically be subtracted from each individual supplier’s inventories.
The Inventory Buffer is a Global Setting which means it refers to the entire installation including all websites and stores you have attached to Magento.
dropship360 changes the way your inventory is calculated. It updates individual Qtys for each supplier as an aggregate count based on Qtys of the same product for all suppliers. The Inventory Buffer subtracts from each vendor’s Qtys.
If Supplier 1 has inventory 15 a product and Supplier 2 has inventory 20 of the same product dropship360 will show a total inventory of that product as 35.
You will be able to see this total under Catalog > Manage Products > select a product > Product Information > Inventory.
An Inventory Buffer of 3 is set. Supplier 1 uploads inventory Qty of 15 for a product and Supplier 2 uploads inventory Qty of 20 for the same product. The aggregate total will be 29. Supplier 1: 15 minus buffer 3 = 12 plus Supplier 2: 20 minus buffer 3 = 17 which totals 29.
Note: The Inventory Buffer is only calculated upon a Qty update. If you change the Buffer amount you must wait for an inventory update to take effect before the new Buffer amount will be calculated into the total inventory.