Platform-Independent File Names in Programs  

...

       1.      Ensure that the logical file names which you want to use have definitions in the system, which convert them into platform-specific file names. Use the transaction FILE, to check existing definitions or create new ones (see Application Server ® System Administration ®  Platform-Independent File Names, in the IMG.)

       2.      Ensure that the physical paths specified in these definitions, exist in the runtime environment file system. Create the required directories, or contact your system administrator.

       3.      Test the file name conversion by calling the function module in the individual test of transaction SE37.

       4.      Put a call to the function module in your program (by calling the function Edit ® Model Command in the ABAP/4 Editor).

Information about saving files in the application and presentation server is in Using files in the ABAP/4 User Handbook.

Creating a syntactically correct platform-specific file name does not in itself guarantee the successful saving of a file. The path must also actually exist in the file system at run-time.