The R/3 enhancement concept allows you to add your own functionality to SAP’s standard business

applications without having to modify the original applications. SAP creates customer exits for specific

programs, screens, and menus within standard R/3 applications. These exits do not contain any

functionality. Instead, the customer exits act as hooks. You can hang your own add-on functionality onto

these hooks.

If you want to enhance the functionality of your SAP System, you should take advantage of the exits

available in standard R/3 applications. There are two main reasons why you should use exits rather

than modifying SAP software yourself. Add-ons attached to exits have the advantage that:

• They do not affect standard SAP source code

When you add new functionality to your SAP System using SAP’s exits, you do not alter the source

code of standard SAP programs in any way. The code and screens you create are encapsulated

as separate objects. These customer objects are linked to standard applications, but exist separately

from SAP’s standard software package.

• They do not affect software updates

When you add new functionality to your SAP System using SAP’s exits, your objects

(called customer objects) must adhere to strict naming conventions. When it comes time to upgrade

a to a new software release, customer objects’ names ensure that they will not be affected by

any changes or new additions to the standard software package.

Customer exits are not available for all programs and screens found in the SAP System. You can only

 use customer exits if they already exist in the SAP System. You find find more information about locating

applications with pre-defined exits in Locating Applications that Have Exits.