How To Fix MD_SUBSTN021 - Rule &1 is relevant for applications used also by rule &2

MD_SUBSTN021 - Overview

• Message type: E = Error

• Message class: MD_SUBSTN - Messages for Master Data Substitution

• Message number: 021

• Message text: Rule &1 is relevant for applications used also by rule &2

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message MD_SUBSTN021 - Rule &1 is relevant for applications used also by rule &2 ?

  The SAP error message MD_SUBSTN021 typically occurs in the context of the SAP Advanced Planning and Optimization (APO) module, particularly when dealing with substitution rules in the context of demand planning or supply network planning. This error indicates that there is a conflict or inconsistency in the substitution rules defined for certain applications.
  
  Cause:
  The error message "MD_SUBSTN021 Rule &1 is relevant for applications used also by rule &2" suggests that:
  
  There are two substitution rules defined in the system.
  Both rules are relevant for the same applications or planning areas, which can lead to conflicts in how the system processes data.
  This situation can arise when rules are not properly configured or when there are overlapping conditions that make it unclear which rule should take precedence.
  
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Review Substitution Rules:
  
  Go to the transaction code where you manage substitution rules (e.g., /SAPAPO/SDP1 for demand planning).
  Identify the two rules