The Titan Multi-Site Warehouse extension allows you to manage several stocks on a multi-site installation. If you have multiple sites that share the same SKU between each store you will know the default system will only allow 1 stock quantity per SKU.
However with this extension it enables you to have the ability to have multiple stock QTY for the same SKU. You can have one stock count for each website in your system.
1. Install Extension via Magento Connect Manager;
2. Flush Magento Cache (System - Cache Management);
3. Log out then back into Admin Area to avoid any errors.
Add Stock Locations (Warehouses):
1. Go to (System - Manage Warehouses);
2. Click Add New Warehouse button;
3. Insert Warehouse Code - This will be shown in (Catalog - Manage Products) QTY column, we suggest to keep it short;
4. Insert Warehouse Name - Name this warehouse location.
Set Locations to Web site:
1. Go to (System - Manage Stores);
2. Click on the website name you want to set stock location;
3. In the Warehouse dropdown box, change value from default to one of your stock locations; Save and repeat for other Web sites in your magento multi-site installation.
Edit Stock QTY:
1. Click on the product you want to change stock QTY;
2. Enable product for website: Product Information - Websites - Tick Websites and then Save Settings;
3. Click on the store view you want to edit stock for;
4. Click Inventory, then insert amount into QTY field and save.