topic Setting threshold for forecast in SAS Forecasting and Econometrics

Setting threshold for forecast

cjauregui — Tue, 11 Apr 2017 20:21:33 GMT

Hello,

Is there a way inside Forecast Studio (or another method) to force Forecast Studio to overide the time series forecast for future months to a preset minimum or maximum value when it is out of the threshold only? I'd like to set thresholds so that the forecast will be more reasonable given our expectations.

Thanks!

Re: Setting threshold for forecast

udo_sas — Wed, 12 Apr 2017 12:20:30 GMT

Hello -

You may want to look into using "adjustment variables" - from SAS Forecast Studio 14.2 User's Guide (chapter 6):

"What Is an Adjustment Variable?

Systematic variations and deterministic components are included in time series data. By adjusting the time series for known systematic variations or deterministic components, the underlying stochastic (unknown) time series process can be more readily identified and modeled. For more information about adjustment variables, see the "Adjustment Step" topic in the SAS Forecast Server Procedures: User’s Guide."

Thanks,

Udo

Re: Setting threshold for forecast

mitrov — Thu, 18 May 2017 12:33:38 GMT

Hi:

Note that using min/max adjustments will set a bound to the statistical forecasts. If your project is hierarchical your final forecasts may be different from the statical forecasts. If you need to set bounds on the final forecasts, I can't think of a direct way of doing it inside Forecast Studio.

However, there other ways to accomplish that. Each one requires a bit of coding, but not much. These three come to my mind. There may be other alternatives I can't think about right now.

You can create a stored process to run as a report to post-process the final forecasts and replace the forecasts that exceed the bounds. You can learn about reports here: http://support.sas.com/documentation/onlinedoc/forecast/14.2/fsug.pdf#page=145
You can use the %FSSETOVD macro to set overrides programmatically when the forecasts exceed one your your predefined bounds. You can find more information on the macro here: http://support.sas.com/documentation/onlinedoc/forecast/14.2/fsag.pdf#page=183
The third option is a bit more complex. You can use the CONSTRAINT= option of the HPFRECONCILE procedure to set bounds on the reconciled values. This would have to be done entirely outside the project in order to avoid corrupting the project data. Essentially you have to reconcile the the hierarchy again. You can use the RECONCILE_FORECASTS_DO_NOT_IMPORT_DATA.sas file in the project folder as a template for your code.

Michele