Extending SAP Standard

Hi folks,

I am still struggling with the issue of extending the SAP standard. However I think it is import for a sustainable SAP-Architecture to do it the right way. As far as I know it depends very much from the SAP version.

I know that some SAP Programms contain user-exits and extension points/containers either in the code or in the import-/export-/change-parameter.

But what alternatives exist if there are is nothing like that implemented in the SAP standard?

Do BAdIs provide any possibility to extend the SAP Standard no matter if the report itself is prepared for that.

In real-life example, I like to extend the functionality of a existing SAP function which is at the same time BAPI. I haven't found any user exits or other customer extensions. In first approach I copied the BAPI, modified it and call it from outside. That's probably not the best way.

Does anybody have an suggestion for this specific case or does anybody know of a good source to read more on this topic, maybe with a comparison of possibilities in the different versions?

Thanks in advance

Torsten