Queueing Theory

A queue inside the Pavilion shopping mall. Picture: Motshwari Mofokeng

What drama! I had to renew my Driver’s license. I tried to do this on the Thursday before the Easter Weekend by planning an early 700 am arrival at Rossburgh License Bureau, Durban thinking I will be in the office by 9am. Alas, I was turned away because they already had their days quota. I then drove to Marianhill License Bureau, to stand in long queue till 945am only to find they close at 10am. Being in a forgiving mood I reasoned “No worries – its Easter Weekend after all.”

I try again on the Tuesday after the Easter vacation. I arrive at Marianhill at 6:30 am feeling confident. I ended leaving at 3:10pm having had to stand from 6:30am to 12:20pm due to ceding the very few seats to more deserving folk. No food, no liquid. This had to be one of my most unproductive day in many years. Surely there must be a better way!

I am a natural born queuer. If there is no queue, I am completely lost. I will even form a queue of size one. I do however detest queues. What are queues and why do they work? David Fangudes even pondered “Why do queue norms repeatedly produce informal, yet reliable, order among total strangers unlikely to interact again?” This is a great paper which you can and should read online.

A queue is pragmatic evidence of a service or supply with a shortage. We have physical queues, where one waits for a service. There are even virtual queues which happens while waiting for a service such as a new allocated home or a fibre upgrade. Off course being called to receive a service may in itself lead to a yet another physical queue!

Some queues are logical and inevitable. Consider that there seem to be few alternatives to lining up at an airport boarding gate or to gain entry for a football match.

Uncertainty also plays a decisive role in queue behaviour. The is reason why queues at the boarding gate are usually orderly while there is utter chaos when Checkers has a sale. How much product will each person be able to get? Will the product run out before the queuer gets served? This uncertainty nurtures anxiety, bends elbows often resulting in mayhem.  Further queues impose hidden economic costs on society, particularly the poor who survive on daily wages. Poorly designed queue rules, with little information accentuates matters.

I was on trip to India with a very short stopover at Nairobi. Our fellow passengers were some swamis dressed in bright orange garb and started feeling a sense of calm. This was until the boarding call was announced and all hell broke loose as the sages literally scrambled over us to get into the plane. They clearly knew something we did not know. Thank God for my wife who strong armed her way through an indifferent customs, while literally pulling me through.

Queueing Theory is an important area in Computer Science and has its own dynamics. There is the priority queue, like the one used in casualty wards, where the level of urgency is measured. The First-In, First-Out (FIFO) queue is the queue most of understand. Simply put, the earliest receives the service first. Even my favourite GP has simply abandoned time-honoured appointments and now uses FIFO. His patients  are now victim of his popularity. The Last-In, First-Out (LIFO) is the queue all of us cherish. Tennis balls in a container, and Facebook posts are real-world examples of this method.

Some companies seem to leverage consumer queuing behaviour to their advantage. The controlled release of the latest Apple gizmo or the new Harry Potter book is accompanied by queues which make early ownership attractive to some fans. In this case it is part-theatre, part-advertisement and a dose of me-first.

The single common queue to all cashiers at some chain stores like Game, Makro and Woolworths is a pleasing innovation which reduces faulty teller challenges. On the supplier side it shepherds the customer through a tantalizing series of impulse buying opportunities. A retired CEO of one large company related how he saved (and even made) millions by adopting this method at the behest of cashiers. You see, changing the queueing method removed cashier selection from the customer which  mitigated collusion and coercion. The theory that a cashier is always complicit is wrong and dangerous. The criminal could actually be a thug who coerces the cashier.

What should the License Bureaus do? One common ready solution is retrievable tokens much like a number one is given at some bank branches  or Home Affairs. The token numbers may be issued online or using SMS’s. If one goes to the License Bureau and the computers go off-line, one reuses the token to jump to a higher priority on the next visit. The token should be valid for a limited period. The License Bureau should at the very least inform one through an SMS that one’s Driver’s License is ready for collection. Currently one has  to go back after six weeks and hope and pray that it is indeed there. Add the  2 bucks to the cost of the license application and send an SMS! 

I have a heart-warming queueing incident related to me as I declined a queue promotion at a university while registering my daughter. A very senior academic who while working  at University of Kwazulu-Natal stood in the queue, many years ago to register his daughter.  The administrators on recognizing the academic as second rung senior management quickly went to him and offered to fast track his daughter’s registration. The Professor declined and chose to register as any other family would. That Professor is now the Vice-Chancellor at the Durban University of Technology as well as my boss, Professor Thandwa Mthembu.

Cheers till next, we queue.

Dr Colin Thakur is a digital activist who is committed to the dream of “one person, one connected device.” He is the KZN e-Skills CoLab Director, located at the Durban University of Technology. His areas of research include e-democracy, Social media, and unstructured big data.