How To Fix M3479 - The number of fixed periods is greater or equal to the forecast periods

SAP Error Message - Details

• Message type: E = Error

• Message class: M3 - Material Master

• Message number: 479

• Message text: The number of fixed periods is greater or equal to the forecast periods

What causes this issue?

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

System Response

Number of fixed periods greater than the number of forecast periods
The system sets the number of fixed periods to the number of forecast
periods because it does not make sense to fix more periods than can be
processed in total.
Number of fixed periods the same as the number of forecast periods
No new forecast values will be calculated for the relevant periods in a
subsequent forecast run because the periods are all flagged as fixed.

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 M3479 - The number of fixed periods is greater or equal to the forecast periods ?

  The SAP error message M3479 indicates that there is a configuration issue related to the number of fixed periods in a planning scenario. Specifically, it means that the number of fixed periods you have defined is greater than or equal to the number of forecast periods. This can occur in various SAP modules, particularly in materials management and production planning.
  Cause:
  
  Configuration Error: The settings for fixed periods and forecast periods in the planning configuration are not aligned. Fixed periods are typically used for planning purposes, while forecast periods are used for demand forecasting.
  Data Entry Error: When entering planning data, the user may have inadvertently set the number of fixed periods to be equal to or greater than the forecast periods.
  Master Data Issues: The material master or planning parameters may not be set up correctly, leading to this inconsistency.
  
  Solution:
  
  
  Check Configuration Settings:
  
  Go to the relevant configuration settings in SAP (usually in the SPRO transaction) and review the settings for fixed and forecast periods.
  Ensure that the number of fixed periods is less than the number of forecast periods.
  
  
  
  Adjust Planning Parameters:
  
  If you are using a specific planning strategy, check the parameters related to fixed and forecast periods.
  Adjust the number of fixed periods to be less than the forecast periods.
  
  
  
  Review Master Data:
  
  Check the material master data for the relevant materials and ensure that the planning views are correctly set up.
  Make sure that the planning parameters are consistent with your overall planning strategy.
  
  
  
  Consult Documentation:
  
  Refer to SAP documentation or help resources for specific guidance on configuring planning periods in your version of SAP.
  
  
  
  Testing:
  
  After making changes, perform a test run to ensure that the error does not reoccur and that the planning process works as expected.
  
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may address this specific error or provide additional guidance.
  User Forums: Consider visiting SAP community forums or user groups where similar issues may have been discussed.
  Training: If this is a recurring issue, consider training for users involved in planning to ensure they understand how to configure and manage planning periods correctly.
  
  By addressing the configuration and ensuring that the number of fixed periods is appropriately set, you should be able to resolve the M3479 error.