Every day improved. Could that just be luck?

Queue times are paired data with a skew problem: the same Monday compared with the same kind of Monday, but never bell-shaped. Wilcoxon Signed-Rank is the paired test that does not care about the bell.

SaaS Starter Statistics free

After you install, this is the model to open.

Did the New Process Cut Ticket Times?

  1. In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
  2. Click Start from a template and put that name in the search box.
  3. Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.

The answer

A clean sweep, quantified:

Days improved
9 of 9
W+ statistic
45 the maximum
p (two-tail)
0.009
Median cut
4 hours/ticket

W+ of 45 is every single pair improving, and the p-value prices that sweep at about one in a hundred under pure luck. The median improvement of 4 hours per ticket is the number for the ops review. Deploy times, checkout durations, patient waits: anywhere before-and-after meets skewed numbers.

The model

Average resolution hours for nine matched weekdays before and after the support team added a triage step. The test ranks the differences and asks whether the signs could be luck.

Before15 to 26 h per ticket
After13 to 19 h per ticket
W+ statisticcalculated
Median improvementcalculated

Once it is in your sheet

  1. The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
  2. Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
  3. Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.

Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.