Thanks for attaching the sample data. I think the first step is that we need to use Tableau's Pivot function on the Prod Value columns. After initially connecting to the data source we can pivot these columns like this:
After doing the pivot we can then rename the columns to something a little bit more appropriate:
Once we have the data restructured we can quickly build out a sparkline chart (not sure if this was your desired chart type or not but it seemed fitting given your data ) by bringing Site ID and Production Value onto Rows, and then a Continuous Dimension copy of Days onto Columns.
The final step is to double-click the Production Value axis and enable the Independent axis range option:
And then voila! We've got our final viz without needing to do any complicated calculations
I've also attached a copy of the workbook. Hope this helps get you started and welcome to Tableau and the Forums!
Running Sum Problem_REVISED.twbx 19.9 KB