This functionality is new as of version 4.0.
Purchase Order Items can be added for Products that have reached their 'Minimum Quantity'.
Refer to Configure Inventory Minimum Quantity.
To Add Items Below Minimum Quantity to the Purchase Order:
Create a ‘New’ Purchase Order.
Click the ‘Add Items Below Minimum Quantity’ button.
Confirm the action.
Click the ‘Add Items Below Minimum Quantity’ button.
The Products that have reached the Minimum Quantity will be added as Purchase Order Items.
The 'Ordered Qty(1)' will be automatically populated with a value equal to: