User exits

What are user exits?

What is involved in writing them? What precautions are needed?
User defined functionality included to predefined SAP standards. Point in an SAP program where a customer's own program can be called. In contrast to customer exits, user exits allow developers to access and modify program components and data objects in the standard system.

On upgrade, each user exit must be checked to ensure that it conforms to the standard system.
There are two types of user exit:
User exits that use INCLUDEs.
These are customer enhancements that are called directly in the program.
User exits that use tables.
These are used and managed using Customizing.
Should find the customer enhancements belonging to particular development class.


What are the different ways in which you can make changes to SAP standard software ?

Customizing
Enhancements to the SAP Standard
Modifications to the SAP Standard
Customer Development

What is customizing?

Customizing is the setting of system parameters via SAP's own interface.

Why do you need enhancements?

The standard applications do not offer some of the functionality you need. The R/3 enhancement concept allows you to add your own functionality to SAP's standard business applications.

What are the different types of enhancements ?

Enhancements using customer exits
Customers' potential requirements which are not included in the standard software are incorporated in the standard as empty modification 'shells'. Customers can then fill these with their own coding. Enhancements can relate to programs, menus and screens. Upward compatibility is assured.

In other words, SAP guarantees that the jump from the standard software to the exit and the interface which call the exit will remain valid in future releases.

Enhancements to ABAP/4 Dictionary elements
These are ABAP/4 Dictionary enhancements (creation of table appends), text enhancements (customer-specific key words and documentation for data elements) and field exits (creation of additional coding for data elements).

What is customer development ?
Creating customer-specific objects within the customer name range.

What is SSCR ?
SSCR (SAP Software Change Registration) is a procedure, for registering all manual changes to SAP source coding and SAP Dictionary objects.

What is the difference between modifications and enhancements ?
Modifications mean making changes to the SAP standard functionality.
Enhancements mean adding some functionality to SAP standard functionality.

What are the disadvantages of modification ?
Modifying standard code can lead to errors
Modifications mean more work during software upgrades

What are the advantages of enhancements ?
Do not affect standard SAP source code
Do not affect software upgrades

when do you opt for modification ?
Customer exits are not available for all programs and screens within the R/3 standard applications. You can only use exits if they already exist within the SAP R/3 System . Otherwise you have to opt for modifications .

What are the various types of customer exits ?
Menu exits
Screen exits
Function module exits
Keyword exits

What is a menu exit ?
Adding items to the pulldown menus in standard R/3 applications .

13.What is a screen exit ?
Adding fields to the screens within R/3 applications. SAP creates screen exits by placing special subscreen areas within a standard R/3 screen and calling a customer subscreen from within the standard dynpro's flow logic.

What is a function module exit ?
Adding functionality to R/3 applications. Function module exits play a role in both menu and screen exits.

What is a keyword exit ?
Add documentation to the data elements of key words defined in the ABAP/4 Dictionary. The system displays this documentation whenever a user presses F1 to get online help for a screen field.

How do SAP organizes its exits ?
SAP organizes its exits in packages that are called SAP enhancements. Each SAP enhancement can contain many individual exits.

What is an add-on project ?
To take advantage of the exits available within standard R/3 applications, you need to create an add-on project. This project lets you organize the enhancement packages and exits you want to use. The add-on project also allows you to hang add-on functionality onto the exit hooks contained with SAP enhancements.