Fixed Asset:Add another child but with different depreciation date

I have a business scenario in Fixed Assets which I am seeking your kind inputs.

We have a machine (set as parent item) and attach a child item to it. Depreciation started running and few months later on, we bought another unit of the same child item. Finance would like to increase the unit of child item (using same asset number, since its the same model but just additional unit) but the second child would need to start depreciation at later date. It seems like JDE does not allow the same child (same asset number) to depreciate accordingly, it only has 1 date field to start depreciation. It is not logic for the second child