How to manage the queue in the banking hall

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

11 June 2006

It is very annoying to stand in a slow-moving queue in a bank and then notice that only three the twenty available counters are open. It happened to me recently and I decided to make good use of all the negative energy generated; I analysed the scene thus.

When I joined the queue, there were almost 80 people waiting to be served. I estimated this from the fact that the queue had looped three times (forming a figure “S”) and I counted 24 people in one loop. 24 times three is 72. Adding the three or four people at the bends of the loops and the total comes close to 80.

It took about half an hour to advance along one length of the figure “S”. That is, about 25 people served in 30 minutes. This can be seen in two ways: first, the bank was serving 50 customers per hour or, alternatively, it was taking an average of 72 seconds to serve each customer.

The bank in question has eleven counters but only five were open. However, one of the tellers kept walking away from her station thus I figured that there were effectively four and a half cashiers. When working together the tellers were taking 72 second to serve one customers, therefore, each was taking over five and a half minutes per client. That is, about 11 clients per hour per cashier.

In one hour, I had advanced about 50 places but the queue behind me had grown longer by about 40 people to a total of 120. This means that the speed of service was slower than the rate at which new customers were joining the line. In that period of time, 90 people came into the bank and 50 left – the net change was therefore an increase of 40.

By the time I was served, the total length of the queue had grown to about 150 – almost double what I found when I walked in. What if the manager had seen the problem and opened just one more counter and also dealt with the disappearing cashier?

The speed of service would have increased by a factor of 4.5 divided by 6. This is because the number of tellers has increased from 4.5 to 6. That is, they would have served about 67 people per hour and my waiting time would have been reduced by more than 22 minutes.

In order to stop the queue from growing any longer, the bank would have had to serve at the rate of 90 customers per hour. This would have required a total of about eight tellers. With this increased number, my waiting time would have been cut from 90 to 50 minutes (almost half) thereby reducing the frustration by a big margin. Perhaps if that were the case I wouldn’t have gotten the inspiration to analyse the scene…every cloud has a silver lining.