3 Replies Latest reply on Nov 19, 2012 9:09 AM by stephen.mcdaniel.1

    FORECASTING PLOT

    Yonel Letellier

      Please Help:

       

      In the attached workbook, I have a table with the following:

      - Trends of 2012 ADB and New Accounts Actual numbers from Jan - Sep 12, and Outlook (forecast) from Oct - Dec 12 (disregard these 3 months data please)

      - 2 formulas to forecast ADB from Oct 12 to Dec 15 (The 2 formulas have the same forecasting method)

      I called the last month with actual data "_CM_Actual" (in this case Sep12)

       

      I need to apply the forecasting formula values only to Oct 12 - Dec 15 using either forecasting formula. Please note that the initial forecasting periods (in this case Oct 12) will change every month as the actual numbers come in, e.x; next month the actuals months will be Jan - Oct 12, and forecasted values will be Nov 12 - Dec 15

      Then show all values actual of Jan-Sep 12 + forecasted values of Oct 12-Dec15 in one trend line.

        • 1. Re: FORECASTING PLOT
          Ben Porter

          Yonel,

           

          Based on the size of your data set, the easiest thing to do is calculate the forecast in Excel, add a "Forecast Column" (e.g., forecast/actual), then in Tableau drop the forecast column into the color shelf.  See workbook for example. 

           

          There is probably a very complex way to do this in Tableau with some type of really well thought out parameter and table calculation solution; but if it takes you 8 hours to figure out and code vs 2 min a month to do in Excel, your ROI has a long tail. 

           

          Good KB article here

           

          http://community.tableau.com/thread/111348

           

           

          I try to avoid forecasting in Tableau if I can help it.  Now in Tableau 8 they are introducing a forecasting module which will create a few simple forecasts, which I'm excited for!

          • 2. Re: FORECASTING PLOT
            Yonel Letellier

            Thanks Ben,

             

            But I really need to do it in Tableau because this is not only for reporting and visualization, but also for “What If” scenarios that are built into a economic forecasting model with several variables and inputs which work very good in Tableau, but I cannot figure out how to calculate the future values and the plotting.

             

            Yonel

            • 3. Re: FORECASTING PLOT

              Hi Yonel,

               

              Thanks for sharing your example.  There are some new features in the Tableau 8 Beta that can potentially help.  However, I strongly advise adding another two years of historical data.  This would be of great help in either formulating an "expert" (i.e.-human estimated forecast) and in actually computing an accurate statistical model forecast.  My biggest fear is the seasonality of your data is unknown without two complete years of data and in many business scenarios, this is often critical to good forecasts.

               

              If you could repost this and send me a quick e-mail at (split up to stop robots from reading it)

               

              smcdaniel

              @

              TableauSoftware

              .com

               

              that would be great.

               

              Best regards,

              Stephen McDaniel

              Director of Analytic Product Management

              Tableau Software