Track Cancel Lines

 Hi,

We have scenario like 

1-Customer order 3 items received customer PO and create SO with the requested items and booked.

2-while checking the available quantity just 2 items are available and third item is out of stock.

3-we cancelled third item and process with the available items

but management want to track these cancelled items also for future when stock will be available.

How to handle this requirement need your expert opinion.

Regards

Khurram