How To Fix PR402 - Forecast values will be negative

SAP Error Message - Details

• Message type: E = Error

• Message class: PR - Forecast: Help messages

• Message number: 402

• Message text: Forecast values will be negative

What causes this issue?

The historical time series and the current forecast model will produce
negative forecast results.

System Response

The forecast results will be shown in the system as 0.

How to fix this error?

You may find that you obtain more satisfactory forecast results by
choosing a different forecast model.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message PR402 - Forecast values will be negative ?

  The SAP error message PR402, which states "Forecast values will be negative," typically occurs in the context of demand planning or forecasting within SAP's Advanced Planning and Optimization (APO) module or similar functionalities. This error indicates that the system has calculated forecast values that are less than zero, which is not permissible in most forecasting scenarios.
  Causes:
  
  Negative Historical Data: If the historical sales data used for forecasting contains negative values, it can lead to negative forecast values.
  Incorrect Forecasting Parameters: The settings or parameters used for the forecasting model may not be appropriate, leading to unrealistic forecast calculations.
  Data Entry Errors: Manual entries in the master data or transaction data that are incorrect can result in negative forecasts.
  Seasonality and Trends: If the model is not correctly accounting for seasonality or trends, it may produce negative forecasts.
  Demand Planning Settings: The settings in the demand planning area, such as the forecast model or algorithm, may not be suitable for the data being analyzed.
  
  Solutions:
  
  Review Historical Data: Check the historical sales data for any negative values and correct them if necessary. Ensure that the data is clean and accurate.
  Adjust Forecasting Parameters: Review and adjust the parameters of the forecasting model. Consider using a different forecasting method that is more suitable for the data.
  Data Validation: Implement data validation checks to prevent negative values from being entered in the first place.
  Modify Forecasting Model: If using a statistical model, consider changing the model type or adjusting the settings to better fit the data characteristics.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on the forecasting model being used and how to configure it correctly.
  Use Constraints: If applicable, set constraints in the forecasting process to ensure that forecast values do not go below zero.
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  Training and Documentation: Review SAP training materials or documentation related to demand planning and forecasting to better understand how to configure and use the forecasting tools effectively.
  Community Forums: Engage with SAP community forums or user groups where similar issues may have been discussed, and solutions shared.
  
  By addressing the underlying causes and implementing the suggested solutions, you should be able to resolve the PR402 error and generate valid forecast values.