The same question, coded three different times.
In any long-running SAP estate, the same business question — "give me all materials with this profile, anywhere we have data on them" — has to be answered out of three places: the live database, the archive, and a handful of sister systems reachable only over RFC.
So three separate reports get written. Each one with its own SELECT, its own selection screen, its own ALV. None of them know about the others. Comparing the results is a copy-paste-into-Excel exercise. And when a field changes, all three reports drift apart.