OBIEE 12c 12.2.1.2.0 - How to get forecast function working for small time intervals?

Chris|ger

Hello everyone,

i'd like to know whether it is possible to debug the forecast function, included in Oracle 12c as forecast seems to be incorrect, if the forecast is based on just a few Input values (e.g. < 10 time values ).

Is there a possibility to get forecast working for time intervals  with less than 10 time periods (years, months etc.)?

Background Information/Example:

I built an simple test answer, trying to forecast business revenues for 3 years ahead, based on the last 5 business years.

Forecast results seemed fine, when the forecast was based on a lot of input values (e.g. more than ten years). But when there were less input values (e.g. less than 10 years), then forecast-values stayed the same for every year.

OBIEE 12c Version used: 12.2.1.2.0 (on premise)

Simple test answer:

The answer includes 3 columns: Time.Year, Facts.Revenue, Forecast

My column formular for the forecast column looks like this:

Forecast column formular
FORECAST("Facts"."Revenue", ("Time"."Year" timeYear),'forecast','modelType=arima;numPeriods=3;')

This is what the results looked like, when there was no filter on the year column. Results seemed to be ok/ as expected.

Year	Revenue	Forecast
2005	100.000
2006	110.000
2007	120.000
2008	130.000
2009	140.000
2010	150.000
2011	160.000
2012	170.000
2013	180.000
2014	190.000
2015	200.000
2016	210.000
2017		220.000
2018		230.000
2019		240.000

Decreasing the time interval by putting a filter on the year column (e.g. YEAR >= 2012) instead, led to wrong results. Forecast was the same for the years 2017, 2018, 2019.

220.000

Year	Revenue	Forecast
2012	170.000
2013	180.000
2014	190.000
2015	200.000
2016	210.000
2017		220.000
2018		220.000
2019		220.000

Nachricht geändert durch 1454010

Message edited