September 1, 2016
I currently have a static data set for sales transactions which spans 3yrs from August 2013 to July 2016. This data then feeds into a dashboard which shows the average trend data by month and includes a slicer for the user to select the period they wish to view (Jan - Dec). Part of the dashboard shows the average sales per month simply by dividing the total sales values for all of the individual months by 3 and presenting sum value (i.e. average sales that occur in January over the last 3 yrs, etc.).
The two problems that I have are as follows:
a) The user would like to see average trend data but also wants to be able to drill down to a specific year; however, if I include an additional slicer to filter by year then I would need to show the full sales values occurring in that period and this would currently only return a third of the total. If the user selects several years then I need to show the average sales for each individual month over the period covered (i.e. 2yrs then total January sales divided by 2, etc.).
b) Using power query and scheduled downloads I am hoping to set this up so that the data set updates regularly. Once set up then the number of months covered in the data set will vary (i.e. if I could update now I would have 3 x September to July, 2013 - 2016 and 4 x August values, 2013 - 2016). Again I would need the trend data to calculate the number of individual months it is showing data for and average accordingly (including the effect of any slicer filter).
Reading back through the above I realise that the above may be a little confusing but if it is understandable then any suggestions on whether this is possible would be appreciated!
July 16, 2010
I'd set up some separate charts for the user to view the specific year so you're not having to mess with averages. I would also only ever show the average of the last 3 years, as opposed to some averages being over 3 years and others being over 4 years. Surely anything older than 3 years is starting to lose relevance.
Perhaps your average chart can be for a fixed 12 month period and the other chart can be the one that is interactive and allows them to choose which year they want to view.