2 Replies Latest reply on Dec 29, 2016 3:24 PM by stephen.ta.0

    Forecasting based on historical averages based on week and year

    stephen.ta.0

      Hi,

       

      I am trying to replicate a forecast that is currently built in excel and move it over to tableau.

       

      One of the roadblocks I am having is applying the 3 yr average to our current weeks data.

       

      The data is by week # of the year and I want to apply the average over the last 3 years.

       

      For example in 2013 I want to see the % change of week 2 compared to week 1 and etc for 2014 and 2015.  I then want to take the average % change from the last 3 years to forecast that for the next year by applying that new calculated field to last weeks ending amount. 

       

      thanks

       

        

      DateEnding Amount
      7/6/2012100
      7/13/2012120
      7/20/2012100
      7/27/2012110
      8/3/2012130
      8/10/2012135
      8/17/2012115
      8/24/2012145
      8/31/2012150
      7/5/2013120
      7/12/2013100
      7/19/2013130
      7/26/2013120
      8/2/2013115
      8/9/2013135
      8/16/2013140
      8/23/2013155
      8/30/2013150
      7/3/2015170
      7/10/2015180
      7/17/2015130
      7/24/2015140
      7/31/2015120
      8/7/2015150
      8/14/2015110
      8/21/2015120
      8/28/2015125