2 ms·
> Mathematically a single queue is far more efficient. No. In the absence of behavioral effects such as the ones suggested here, the reason to have a single q
by ScottBurson 10y ago
> Mathematically a single queue is far more efficient.
No. In the absence of behavioral effects such as the ones suggested here, the reason to have a single queue is not to reduce the mean time for a customer to check out, but to reduce the variance. With one queue per cashier, if you happen to get behind the person paying entirely with pennies, you're screwed. With a single queue, the additional latency introduced by such a customer will be distributed among all the customers who aren't being served yet, rather than just the few people behind them in the same queue.
- jedberg 10y agoBut it's the variance that you want to reduce if you want to be more efficient about resource usage (ie. cashiers and cash machines). As variance goes up, your overhead for burst capacity goes up. Also, variance is what people perceive as bad service, not the mean time. If everyone takes a little longer they feel happier because of the perception of fairness.