Fiori - Contract Leakage (Procurement)

Hi.

I am looking to use the following Fiori app:

Contract Leakage (F0681)

Whilst this looks very useful, I need to be sure how the data is calculated: i.e. what metrics are used within the app to determine that an available contract has not been used.

I am guessing at the moment that this would be a look-up between perhaps Material Group and Vendor, but I cannot see any information as to how the system determines that a potential contract has been bypassed....

Thank you