The New York Times (23 June 2007) has an interesting article on how Whole Foods has begun to use a single line for check-out which feeds various cash-tills instead of a separate line at each cash-till leaving shoppers to guess the fastest moving line!
Banks have long used a single line to manage queues at the tellers.
While at first glance, a single line as opposed to multiple lines would not seem to make a huge difference. However, data from the article proves otherwise.
From the article:
“The single-line, bank-style system was quickly chosen for its statistical efficiency. Then, Whole Foods paired the system with possibly the largest number of registers in the city, more than 30 per store, and it hired an army of cashiers to staff them throughout the day (including “floaters” to fill in for those who need a break).”
“The result is one of the fastest grocery store lines in the city. An admittedly unscientific survey by this reporter found that at peak shopping times – Sunday, from 4 p.m. to 6 p.m. – a line at Whole Foods checked out a person every 4.5 seconds, compared with 19.6 seconds for a line at Trader Joe’s.”
“Perhaps the most important role players in the Whole Foods system are the “line managers,” who monitor the flow of people, direct them to a cash register and, when needed, hold up signs saying how long it will take to check out. In another innovation, color-coded digital screens are now replacing those humans.”