How To Fix CNV_10020020 - &1 &2: Maximum cardinality was not maintained

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV_10020 - Message class for package 10020

• Message number: 020

• Message text: &1 &2: Maximum cardinality was not maintained

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message CNV_10020020 - &1 &2: Maximum cardinality was not maintained ?

  The SAP error message CNV_10020020 typically occurs during data migration or conversion processes, particularly when using the SAP S/4HANA Migration Cockpit or other data migration tools. This error indicates that the maximum cardinality of a relationship between entities (such as tables or data structures) was not maintained, which can lead to inconsistencies in the data model.
  Cause:
  
  
  Data Model Inconsistency: The error often arises when the data being migrated does not adhere to the defined relationships or constraints in the target data model. For example, if a one-to-many relationship is violated by having more entries than allowed in the target structure.
  
  
  Incorrect Mapping: During the mapping of source data to target structures, if the cardinality constraints are not correctly defined or respected, this error can occur.
  
  
  Data Quality Issues: The source data may contain duplicates or unexpected values that violate the cardinality rules of the target system.
  
  
  Solution:
  
  
  Review Data Model: Check the target data model to understand the cardinality constraints defined for the entities involved. Ensure that the source data aligns with these constraints.
  
  
  Data Cleansing: Before migration, perform data cleansing on the source data to remove duplicates or correct any inconsistencies that may lead to violations of cardinality.
  
  
  Adjust Mapping: If the mapping of fields between source and target is incorrect, adjust it to ensure that the relationships are maintained according to the target data model.
  
  
  Use Migration Tools: Utilize SAP's migration tools effectively, ensuring that you follow the guidelines for maintaining cardinality. This may include using the correct migration objects and ensuring that the data is loaded in the correct sequence.
  
  
  Testing: Conduct thorough testing of the migration process with a subset of data to identify and resolve any issues before performing a full migration.
  
  
  Consult Documentation: Refer to SAP documentation or notes related to the specific migration scenario you are working on, as there may be specific recommendations or known issues related to the error.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may provide additional insights or solutions for this specific error.
  Migration Cockpit: Familiarize yourself with the SAP S/4HANA Migration Cockpit and its functionalities, as it provides tools and guidelines for successful data migration.
  Community Forums: Engage with the SAP Community or forums where other users may have encountered similar issues and can share their solutions.
  
  By addressing the underlying causes and following the recommended solutions, you should be able to resolve the CNV_10020020 error and successfully complete your data migration.