Use Up Item Number

Hi,

I try to understand usage of "Use Up Item Number" field in Enginnering Change Order --> Use Up Details

Full path: Development Manager --> Change Management --> Create Change Order --> Add Revised item -->

click Details subtab.

Next click Update Revised items and open the List of Values for the "Use Up Item Number" in "Use Up Details" section. Select item number.

Could you explain how this field works and what advantages it has ?

Thanks