The canteen queue

Every school canteen has the same problem. Everybody arrives at once, the queue reaches the door, and by the time the last students are served the break is nearly over.

One school tried an unusual fix. It did not hire more staff or buy another till. It moved the drinks.

Someone had watched the queue for a week and noticed that it was not one queue but two problems overlapping. Students buying a full meal took around forty seconds each at the counter. Students buying only a drink took about eight. The drink buyers were roughly a third of the queue, and every one of them was waiting behind people whose business took five times as long.

The drinks were moved to a separate table with its own cash box near the door. The main queue lost a third of its length immediately, and because the remaining customers were all doing similar transactions, the counter staff stopped switching between tasks and got faster as well. Average waiting time fell by more than half.

Nothing was added. No money was spent beyond a table. The improvement came from noticing that putting fast customers and slow customers in the same line makes everybody wait, and that the fastest way to shorten a queue is often to stop one queue being two.