History replacement engine results

The algorithms consider these factors to generate replacement history values:

  • Simple Mean: Considers the mean of history data before the derived period start index and uses this value for all replacement periods.
  • Simple Naive: Considers the previous (most recent) history point value before the derived period start index and uses this value for all replacement periods.
  • Simple Past Year: Considers the history value from the same period of the previous year.
  • Simple User-defined: Applies the specified value in the measure mapped to User-defined Value and uses this value for all replacement periods.
  • BATS: Forecasts the replacement periods with BATS, using the history data (before the derived period start index).
  • Linear interpolation: Forecasts the replacement periods with linear interpolation, using the history data (before the derived period start index).
  • Offset Forecast: Applies the offset forecast value for the same period, for all replacement periods, using values in the measure mapped to Offset Forecast.
Based on the History Replacement Engine measure mappings, the engine retrieves the output from the engine result set and applies this output to SCP scenario values of the mapped Replacement History measure.The returned history values are normalized using the specified period weightings vector for the cycle period history horizon, prior to saving the output values in SCP. This is done externally to the engine.
Note: User-Defined Value input is static (at pconst), not time-phased. Since the user-defined value can be applied to several periods and the returned history values are normalized, the replaced history values may differ from the User-Defined Value across periods at the engine's Period Level.

For example,

Consider Period Level = Months, Periodicity = 12 and 3 history periods to be replaced that correspond to 445 monthly calendar periods (28, 28 & 35 days in the period, respectively). These periods have a weighting factor: 0.923076923, 0.923076923 and 1.153846154, respectively.

User defined value = 50. The normalized replacement history at the Months level, prior to any period proration, if applicable, would be: 46.15384615, 46.15384615, 57.69230769.

The engine output results are written to Cycle Period History horizon. If the engine process ends with errors or warnings, the results are output to the job manager and audit log. A discard log is attached to the audit log message.

Item/locations which require proration of output results are verified to make sure that the corresponding spread measure contains values. Else, an error is recorded in the discard log with a suitable warning message.

Note: 
  • Individual item/location errors do not prevent the processing of valid combinations.
  • Unsuccessful item/location combinations, either from the SCP validation or returned with an error or warning code from the engine, are recorded in the discard log with an error message. For example: 
    “No history has been provided for this history replacement method.”