How to track item attribute updates

Summary:

We have a requirement on PDH side, how can we track the changes of item attribute updates / structures related changes?. They follow change order process for some of them, most of them are through item import map (without change order) 

Currently, business users are manually capturing the change reference details at item level EFF through import map. But it will be overwritten and they can't retain the old reference.  

We are exploring on enabling audit, creating a change order automatically during item batch creation, or exploring expression related option on item import map. What are the best practices for this requirement? Could you please suggest. Also, any limitations with existing options which we are exploring. Thank you!