When a GRN is done, a part of the inventory is reserved against one or few orders. Those GRND stocks won't be available for standard fulfilment as they are reserved and can only be fulfilled to the customers/orders for which it was reserved.
Steps to reserve inventory
- Go to the PO Listing
- Find the PO that is ready to Receive. Go to the receive tab
- Fill in the required information & then click on IsReserved
- This will give you an option to search for unfulfilled order and qty with comment