Checking and Activating Modules 

Before you can activate a function module, you must check to make certain that the module's syntax is correct. Open one of the module's interface screens and use Function module ® Check to check your module. Checking Source Code explains in detail how to use this feature.

Newly created function modules are automatically set to Inactive.

If a function module is inactive, the normal syntax check only checks that module. If you want to check the module as part of the whole function group without activating it, choose Function module ® Check ® Main program. The check program checks all of the function modules and include programs regardless of whether they are active or inactive.

To activate a completed function, choose Function module ® Activate. An activated function module is included in all syntax-checking for the module's entire function group. When the system checks an activated function module's syntax, the system actually applies the check to all activated members of the function group. When you activate a function module, syntax-checking is performed automatically.

Inactive sources in the ABAP Workbench.