Can't say that I've used them directly beyond the aforementioned SUM and AVG, etc., as I prefer to create a data set for the people who want to do analysis and let them work the formulas in Excel or whatever.

However I did recently engage two of my colleagues to evaluate a solution I developed about a year and a half ago to track certain labor data. They're both very well-versed in process improvement and statisitical analysis and I understand enough about both to be dangerous.

It's exciting and a little scary at the same time (this project is my baby) but I'm looking forward to the experience. Since the database it's built on is in Full Recovery with hourly t-log backups, I've toyed with the idea of "going back in time" and rolling it forward (in a non-production environment, of course) by intervals to simulate changes over time (hmm...interesting idea for a script...). I also took an on-line statistics course last year that had an optional module on R which I took but never really had a reason to use until now.

It'll be fun.