Apply Object Oriented ABAP in extractor and variable exits
Here are a couple documents that shed light on the benefits of OO ABAP, and how it can be used in SAP BW. The documents describe the advantages of the Object Oriented approach and provide step by step instructions on how to implement it in BW 7.x.
Document from Suneel Kumar Reddy Sannala describing ECC extractor user exits enhancement with BADIs:
Document from Federico Cattaneo describing the process of BEx variable user exits creation:
