Converting an SAP ECC system to S/4HANA is a complex brownfield migration that often focuses on obvious challenges like module functionality and database migration. However, lurking beneath the surface are invisible failures subtle technical issues that don’t immediately break the conversion process but later sabotage operations. These failures often stem from overlooked technical details, such as legacy custom code or data quirks, and teams miss them because they aren’t caught by standard checks or superficial testing.
Legacy Custom Code Pitfalls Hidden in Plain Sight
One of the biggest sources of hidden issues is custom ABAP code carried over from ECC. Even after a successful syntax adaptation, legacy code can harbor logic that silently malfunctions in S/4HANA: