I've been participating in Makeover Monday for a few weeks now, and this week I was determined to use calculated fields.
My first thought was to do something along a control chart vein. Tableau provides ways to show the average along with the upper and lower limits, but a couldn't find a way to show a process shift with new averages, etc. within the chart. I resisted the urge to manipulate the data in Excel and managed to break the data into ranges. And then I hit a wall. There was no way to turn my calculated field into a dimension I could use to define the ranges in the chart. I'm now beginning to see why there is some data manipulation tool listed along with Tableau in job postings.