How To Fix W8020 - The interface of function module '&1' does not correspond to conventions

W8020 - Overview

• Message type: E = Error

• Message class: W8 - Workflow: Expressions, data flow

• Message number: 020

• Message text: The interface of function module '&1' does not correspond to conventions

What causes this issue?

Function module &VA1& does not correspond to the convention for program
exit for dataflows. The function modules for dataflow have an adjusted
interface which must be as follows:
Import parameters
DATAFLOW with reference SWABINDEF-DATAFLOW
Table parameters
CALLED_CONTAINER with structure SWCONT
CALLING_CONTAINER with structure SWCONT

How to fix this error?

You should adjust the binding function module to accord with this
convention or use the function module SWA_TEMPLATE_EXECUTE_DATAFLOW as
a copy model.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message W8020 - The interface of function module '&1' does not correspond to conventions ?

  Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  W8020 - The interface of function module '&1' does not correspond to conventions
  
  
  Cause:
  This warning occurs when a function module's interface does not comply with the expected interface conventions defined by SAP for certain types of function modules. Typically, this happens in the context of Remote Function Calls (RFCs), BAPIs, or other standardized function modules where SAP expects a specific parameter structure, such as:
  
  Importing parameters
  Exporting parameters
  Tables parameters
  Changing parameters
  Exceptions
  
  If the function module interface deviates from these conventions (e.g., missing parameters, wrong parameter types, or incorrect parameter directions), the system issues this warning.
  
  Common scenarios causing W8020:
  
  The function module is intended to be used as an RFC or BAPI but does not follow the required interface pattern.
  The function module is missing the RETURN parameter or has it incorrectly defined.
  The parameter types or names do not match the expected standard.
  The function module is used