ABAP_to_the_Future

I love the baddies. More important, though, is making the baddies
somehow, weirdly, understood.
—Mark Strong
6 The Enhancement Framework
and New BAdIs
Standard SAP code is like Swiss cheese: full of holes. In these holes, you can add
your own code—otherwise known as us er exits—and thus alter the standard
behavior of the SAP system to fit the exact needs of your business.
User exits haven’t always received the a ttention they deserve. In the past, SAP
used to recommend (in certain cases) that instead of creating a user exit you
should make a copy of the standard program, creating a clone that started with a
Z, and make your changes in that copy. Because this was official SAP policy at the
time, many SAP customers did just that and created an army of cloned programs.
Then, SAP belatedly realized this was the worst thing you could possibly do,
because during an upgrade the original program would change (due to bug fixes
and extra functions), but the clone wo uld not. Then came what can best be
described as the clone wars, with cust omers writing clone hunter programs,
which eventually became part of standard SAP.
The revised policy was not to have clones, but to use the Modification Assistant to
insert your changes directly into standard SAP code. Then, during an upgrade, the
SPAU process would recognize such changes and make you decide if you wanted
to keep them or not. This was a lot better, but if you have a fair number of such
modifications to the standard system (and a lot of companies do, even ones with
a “no modification” policy), then at upgrade or support stack time the SPAU process
could take quite a while.
The current—and clearly the best—option is to use a user exit. Modifications to
standard SAP code vanish during an upgrade and have to be manually reapplied,
but user exits of any variety remain.
225