User-exits material

SAP delivers a broad range of business functions within its R/3 application suite. The standard applications may not offer some of the functionality needed. The R/3 enhancement concept allows addition of one’s own functionality to SAP’s standard business applications.

SAP creates user exits for specific programs, screens and menus within standard R/3 applications. These exits do not contain any functionality. Instead, the user exits act as hooks. One can hang his own add-on functionality onto these hooks.

The user exit is a point in a SAP program where a customer’s own program can be called. 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.

Purpose of the Enhancement Concept

With the ABAP/4 Development Workbench, SAP’s client-server development environment, one can create add-ons or entire applications. Before the enhancement concept existed, customers who wanted to add their own specific functions to SAP software had to modify the standard SAP programs. Modifying SAP’s software holds at least two dangers:

Modifying standard code can lead to errors

When a customer changes the source code of a standard program, these changes can have unwanted results within other parts of the application. Once a customer has begun ‘reconstructing’ a standard program, SAP can no longer guarantee that this customer’s system will run without serious errors.

Modifications mean more work during software upgrades

Customers of standard software packages often want to take advantage of software upgrades or new releases. Customers who have modified the software of their current release must save these modifications and reenter them into the new software after each upgrade or release change. Depending on the number and scope of modifications, this reentry process may make it difficult or even impossible to take advantage of new software releases.

The enhancement concept offers a better alternative to the problem-ridden modification approach.

Reason for Using Exits :

If you want to extend the functionality of your R/3 System, you should take advantage of the user exits available within the standard R/3 applications. There are two main reasons why you should use exits rather than modifying SAP software. Add-ons that are attached to user exits have the advantage that they:

Do not affect standard SAP source code

When you add new functionality to your R/3 System using SAP’s user exits, you do not change the source code of standard SAP programs. The code and screens you create are encapsulated as separate objects. These customer objects are linked to standard applications, but they exist apart from SAP’s standard software package.

Do not affect software upgrades

When you add new functions using SAP’s user exits, the objects you develop are customer objects. Customer objects adhere to strict naming conventions. When the time comes to upgrade a software release, the special names of customer objects ensure that they will not be affected by either changes or additions within the standard software package. As a result, you do not need to save and then reenter add-ons attached to user exits.

User exits are not available for all programs and screens within the R/3 standard applications. One can only use exits if they already exist within the SAP R/3 System. Locating Applications that Have Exits explains how to find applications with predefined exits.

If no user exit is available in an area to add a particular functionality, a request can be made to SAP to develop an exit. This request can be made via the Online Service System (OSS).

Navigation

To take advantage of user exits they have to be added to a standard application by SAP. For this reason, it is necessary to know how to locate the exits available within the R/3 System. SAP organizes its user exits in packages that are called SAP enhancements. Each SAP enhancement can contain many individual exits.

From within the ABAP/4 Development Workbench menu choose Utilities ® Enhancements ® Project management. To call up a selection screen that lets one look for the exits available in standard applications, choose Utilities ® SAP enhancements. If no information about the name of specific enhancement packages is available, one can search for all enhancements belonging to a particular development class or to a set of development classes. To list all enhancements in the entire system, the Execute function without specifying any selection criteria is chosen.

LINKS :

http://www.erpgenie.com/sap/abap/code/abap26.htm

http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm

http://www.sapgenie.com/abap/code/abap26.htm

http://www.sap-img.com/abap/what-is-user-exits.htm

http://wiki.ittoolbox.com/index.php/HOWTO:Implement_a_screen_exit_to_a_standard_SAP_transaction

http://www.easymarketplace.de/userexit.php

http://www.sap-img.com/abap/a-short-tutorial-on-user-exits.htm

http://www.sappoint.com/abap/userexit.pdfUser-Exit

http://www.sapdevelopment.co.uk/enhance/enhancehome.htm

http://www.sap-img.com/abap/what-is-user-exits.htm

Hope this resolves your query.