*** How to add a new line item Y to the order when item X is out of stock ***

Summary

How to add a new line item Y to the order when item X is out of stock

Content

Business Case :

• Customer orders item Y
• When Item X is out of stock, Need to add a new item Y to the order. Item X will also be there on the order
• Both Item X and Item Y will be separate lines on the order. It is not an item substitution scenario.
• Item Y will be shipped to the customer immediately
• Item X goes on backorder. Will be reshipped later when onhand is available

Please suggest how to meet this requirement.