What is User Exits and Customer Exits in SAP ABAP

What is Customer Exits ?

Customer exits are "hooks" provided by SAP within many standard programs, screens and menus on which customers may "hang" custom functionality to meet business requirements.  More on this in a moment...

In this tutorial you will learn:

• Types of Customer Exits
• Examples of Customer Exits
• Locating Customer Exits
• Create a Customer Exit
• What is a USER EXIT?

Types of Customer Exits

There are three main types of customer exits:

1. Function Module Exits
2. Screen Exits
3. Menu exits

Function Module Exit:It  allows customer to add code via a function module at a specific location in an SAP application program

Syntax: CALL CUSTOMER-FUNCTION '004'

Screen Exit:  It allows customer to add fields to a screen in an SAP program via a subscreen. The subscreen is called within the standard screen's flow logic.

Format: CALL CUSTOMER-SUBSCREEN CUSTSCR2

Menu Exit: It  allows customer to add items to a pulldown menu in a standard SAP program. These items may be used to call add-on programs or custom screens.

Format: +CUS ( additional item in GUI status )

Examples of Customer Exits

Example of a Screen Exit:

In transaction CAT2 - Time Sheet Entry, HR wishes to include an interactive acknowledgment that knowingly submitting incorrect data is grounds for dismissal.

Example of a Menu Exit:
In transaction SE38 - ABAP Editor, the development team wishes to include a menu link to transaction SE80 - Object Navigator for ease of use.

BEFORE

AFTER

Example of a Function Module Exit:
The company wants the bank details of the Vendors in the Vendor creation to be mandatory event .So it must flash a error message that 'Please Enter the bank details'

BEFORE

AFTER

Locating Customer Exits

In transaction SMOD and look into the details-

Or in transaction SE81 you can use the appropriate application area
 

Create a Customer Exit

To create a customer exit you first need to create a project in transaction CMOD

Later you assign the Customer Exit to your project.

What is a USER EXIT?

User Exit serve the same purpose as Customer Exits but they are available only for the SD module. The exit is implemented as a call to a Function Module. The code is written by the developer.

Well know User Exit in SD is MV45AFZZ

• USEREXIT_FIELD_MODIFICATION - To modify screen attributes
• USEREXIT_SAVE_DOCUMENT - To perform operations when user hits Save
• USEREXIT_SAVE_DOCUMENT_PREPARE
• USEREXIT_MOVE_FIELD_TO_VBAK - When user header changes are moved to header work area.
• USEREXIT_MOVE_FIELD_TO_VBAP - When user item changes are moved to SAP item work area