What does staffing to an average day cost you?

Staffing to average demand looks disciplined and costs money, because bad days are far more expensive than quiet days are wasteful. The optimizer prices that asymmetry instead of arguing about it.

Operations Intermediate Optimization under Uncertainty Pro engine

After you install, this is the model to open.

How Many People Should Be on Shift?

  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.

This one runs on a Pro engine, and every free install includes five full-quality runs on your own numbers, shared across all five Pro engines rather than five for each. After that, Pro is $199/year.

The answer

Minimizing expected daily cost:

Optimal roster
26 agents
Expected cost
$7,180 per day
Staffing to the average (21)
$8,020 per day

Carrying five apparently unnecessary people is about $840 a day cheaper than not carrying them. Note what it does not buy: the desk still fails to clear everything about one day in eight, and that is correct, because clearing the 1,450-ticket day every time would cost more than the failures do. The cost curve is flat between 24 and 27 agents, all of them within about $80 a day of each other, so a rerun may answer 25 instead; anywhere in that band is the same answer.

The model

One agent clears 42 tickets a day at $260. Anything left over costs $34 a ticket in overtime and service credits. Arrivals are a three-point estimate: 520 quiet, 820 typical, 1,450 when a release goes wrong.

Agent capacity / cost42 tickets / $260 a day
Overflow cost$34 per ticket
ArrivalsPERT(520, 820, 1450)
Roster sizeoptimized, minimize cost

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.