Enhancement points - Changing standard SAP code using the implict and explicit enhamcement points

Enhancement points are basically hooks at certain defined points within the ABAP code i.e. at the beginning and end of a FORM. These hooks allow you to attach your own custom code which will be executed as if it had been hard coded into the code using a modification. Unlike hard coded modifications these will not be lost during upgrade or patching exercises.

There are 2 types of enhancements with the enhancement framework:

1. Explicit enhancement points: These are basically hooks already coded into the program by SAP at various points of the code. See program RIAUFMVK for examples of these! These are very easy to implement simply go into enhancement mode of SE80 and right click on the enhancement point where you want to add your code and choose ‘Enhancement Implementation->Create’ Give it a name, description and assign it to a change request (should not be a Z package) and then simply add the code as normal.

2. Implicit enhancement points: These are basically points within ABAP code where an enhancement point is implied, and in which case can be created. Examples of implicit enhancement points are at the beginning and end of FORM’s, at the end of a program, include or function module etc.

Overview

R/3 provides three "customization spots" that allow you to enhance FI/CO features without modifying the standard code. Although often collectively referred to as "user exits," two of the three have different names. SAP Enhancements are used to expand the standard functionality within SAP. Enhancements use function modules and are called from the standard SAP code. Each module in the system has a set of delivered enhancements that help companies expand the standard functionality where they need it. Enhancements were new in release 3.0.

Business Add-Ins are a new SAP enhancement technique based on ABAP Objects. They can be inserted into the SAP System to accommodate user requirements too specific to be included in the standard delivery. Since specific industries often require special functions, SAP allows you to predefine these points in your software.

The use of object orientated code within SAP has lead to new method of enhancing standard SAP code called Business Add-Ins or BADI's for short. Although the implementation concept is based on classes, methods and inheritance you do not really have to understand this fully to implement a BADI. Simply think of methods as a function module with the same import and export parameters and follow the simple instructions below
Steps:

• Always create a new separate include for each Gap in a SAP Enhancement exit
  Separate User Exits allow enable the independent migration of code as part or the promote-to-production path
  
• Using the EXIT statement will terminate processing for all subsequent user exits