How To Fix FRMLMSC221 - Loop: Material &1 is input and output in formula &2

SAP Error Message - Details

• Message type: E = Error

• Message class: FRMLMSC - RMS-FRM: Miscellaneous Messages for Formula

• Message number: 221

• Message text: Loop: Material &1 is input and output in formula &2

What causes this issue?

The material displayed is contained in the formula specified both as an
input material and an output material.
This is taken into account when exploding the relevant graphic. To
calculate the proportions, the system determines the difference between
the values of output and input.
Example
If a formula contains MAT_1 (100 units) as the output material and
input components MAT_1 and MAT_2 in a 20:80 ratio, this can be
interpreted as follows: To create 80 units of MAT_1, you need 80 units
of MAT_2 (the proportion between MAT_1 and MAT_2 is 1).

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message FRMLMSC221 - Loop: Material &1 is input and output in formula &2 ?

  The SAP error message FRMLMSC221 indicates that there is a loop in the formula where a material is both an input and an output. This typically occurs in the context of production planning or formula management, where a material is defined in such a way that it cannot logically be both consumed and produced in the same formula.
  Cause:
  The error arises when:
  
  A material (identified by &1) is defined as both an input and an output in the same formula (identified by &2).
  This creates a circular dependency, which is not allowed in SAP's formula management.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Review the Formula: 
  
  Go to the formula definition in SAP and check the input and output materials.
  Identify the material that is causing the loop (the one that appears as both input and output).
  
  
  
  Modify the Formula:
  
  Decide whether the material should be an input or an output.
  Remove the material from one of the categories (either input or output) to eliminate the loop.
  
  
  
  Check Dependencies:
  
  Ensure that the changes do not violate any other dependencies or requirements in your production process.
  
  
  
  Test the Changes:
  
  After making the necessary adjustments, test the formula to ensure that it works correctly without generating the error.
  
  
  
  Documentation:
  
  Document the changes made to the formula for future reference and to maintain clarity in your production planning processes.
  
  
  
  Related Information:
  
  Transaction Codes: You may use transaction codes like C223 (Change Formula) or C222 (Display Formula) to access and modify the formula.
  Formula Management: Understanding how formulas work in SAP, including the roles of input and output materials, is crucial for effective production planning.
  SAP Help Documentation: Refer to SAP's official documentation for detailed guidelines on formula management and error handling.
  
  By following these steps, you should be able to resolve the FRMLMSC221 error and ensure that your formulas are correctly defined without circular dependencies.