Queue Simulation with Spreadsheets: Arrivals, Service Times & Waiting Lines

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Turn 20 given random numbers into the gaps between customers arriving at the Copperleaf Coffee kiosk, using the inverse of the exponential distribution.
• Add up the gaps into arrival times, convert them to clock times after the 08:00 opening, and check how many customers arrived in the first half hour.
• Draw 20 service times at the kiosk in two ways, exponential and normal with a minimum, and compare the long-service share with theory.
• Build the core of every queue simulation: for each customer the service start, the finish, the waiting time and the time in the system, with one barista.
• Summarise the simulated morning in the four numbers every queueing study reports, and chart the waiting time customer by customer.
• Add a second barista to the same morning: each customer goes to whoever is free first, and you compare the average wait with the one-barista run.
• Calculate the textbook M/M/1 waiting time for the kiosk, average ten long simulation runs and check with a confidence interval whether simulation and theory agree.
• Put a price on waiting, add it to the staff cost for 1, 2 and 3 baristas, pick the cheapest option and show the trade-off in a stacked column chart.