Understanding the Difference Between a Functional Module and a Sub-routine in SAP ABAP

When it comes to SAP ABAP programming, it is crucial to differentiate between functional modules and sub-routines. The key difference lies in their functionality and execution within the program.

Functional Module

A functional module in SAP ABAP is a self-contained unit of code that performs a specific task or set of tasks. It can be called from any program within the SAP system by using the CALL FUNCTION statement. Functional modules are typically reusable and can accept input parameters and return values.

Sub-routine

On the other hand, a sub-routine is a reusable block of code within a program that performs a specific task. Unlike a functional module, a sub-routine is called using PERFORM statement within the same program where it is defined. Sub-routines are useful for organizing code and improving readability within a program.

Focus Keyword: SAP ABAP

In summary, the main difference between a functional module and a sub-routine in SAP ABAP lies in their reusability and method of invocation. While functional modules are standalone units that can be called from any program, sub-routines are specific to the program in which they are defined. Understanding when to use each can help in developing efficient and maintainable SAP ABAP programs.