The Beginner’s Guide to Queuing Theory

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Most of the businesses in Dubai and all around the UAE faces problem with their queue management. It is common to sight long waiting lines and poorly managed queues at service centers, banks, telecom branches, government offices, and even in healthcare and educational institutions. In fact the queues are everywhere in our lives, some of them we might not consider as queues, and some we might address with other names. For example, let us suppose you woke up in the morning, while driving to your office at the road, the congestion and traffic is a queue, you went to a gas station and you stand in a queue to wait for your turn to fill the tank, you arrive at your work and you might see a line at the attendance register or biometrics attendance machine and so on.

We usually don’t realize, but the queues are everywhere and everyone have to face them. Every business belongs to the service industry will have to deal with the queue management problems. When it comes to adopt a modern queue management system the business leaders and managers often get confused due to the sheer number of possibilities available in the market.

Why Learning about Queuing Theory is Important for Businesses?

The queuing is a process where human, information or even material could be the subject waiting in lines for their turn. For example, the cars on a congested road are waiting in queues to pass an intersection, the customer call waiting at a call center is also queue, and the baggage control at the airport is passing your luggage through the queuing lines. All these different scenarios are the examples of the queuing. In this world the time is the most precious commodity, it is irreversible, no one wants to waste it. Businesses don’t want to waste their customers’ time neither their own.

Because wasting time can completely destroy the productivity and cause stressful situations for all concerned parties. Different queuing scenarios are the biggest cause of wasting our time whether it is at the road in traffic jam, or whether it is at a bank, office, service center, university, collage, hospital, hotel, restaurant, movie theater, or anywhere, it simply waste our time and it is very annoying. As queuing cause waste of time which directly impact the productivity that is why it is crucial for businesses to understand queuing theory.

The Queuing Theory

By definition the queuing theory or the queuing model is a study and knowledge of learning about the waiting lines, expected scenarios and queuing behavior based on discrete information, statistical/analytical data and practical assumptions. The purpose of a queuing theory is to measure the efficiency, effectiveness and overall performance of a queue management system. For example the queuing theory help you understand the long term behavior of the queue management system by estimating the average wait time, the probability of the customer flow at any given time period, the performance of the service agent, and service delivery time. This will help you determine the need of the servers and the wait and service delivery time, as per your demands or goals.

For example you will have to make assumption such as inputs the distribution of arrival and service time and the count of the server to implement the formula of the queuing theory to estimate the performance and effectiveness of the queue management system. The queuing theory formula will help you to understand the long term behavior or commonly known as the steady state behavior of your queue management system. The queuing theory or queuing model will enable you to test different scenarios to achieve the perfect match as per you needs and goals.

The Steady State Queuing Behavior

The steady state queuing behavior is due to the assumption that the queue management system doesn’t change anymore and maintain a steady state. It means that the influx, the server performance and various other variables that are used in the mathematical derivations are constant now and give a more rational measurement of the performance. The performance of a queue management system is very difficult to estimate in real-time as in real-time and practical example, there are too many variables and moving parts, which could either improve or hinder the effectiveness of the queue management system and most of them are non-linear. That is the reason the steady state queuing behavior is used to compare two different queue management systems and to test various different scenarios and configurations.

The steady state queuing behavior analysis will help businesses to find out the most perfect and effective queuing setup as per their demands and goals. That is why the queuing theory alone is not enough, hence businesses use simulation technique where they keep changing the state of the queue management system, measure the performance for each state and then take an average to understand the actual performance of a real-world application of the queuing theory.

The Importance of Queuing Discipline

Usually the notion of queuing discipline is first come first serve which is based on two factors, the performance and the fairness. However, that is not applicable all the time, in fact most of the time the businesses tend to utilize different queuing disciplines and more importantly is to understand that the performance of a queue management system can also be improved by utilizing more than one disciplines at a time. Here are the most commonly used queuing disciplines that are popular among the businesses in Dubai and all around the UAE:

First in first out (FIFO): This is the most ancient queuing discipline, whoever will come first should be served first to maximize the performance and fairness.
Last in first out (LIFO): This queuing discipline is most popular for the goods and materials, such as items that are placed in a delivery truck at the last should go out first.
Loop: The loop queuing discipline is popular for non-human queuing, it is being frequently used in the information systems and also in the production environments where every queuing subject needs constant service.
At once: That is also one of the most observed queuing discipline with limited application in the service industry. In ‘at once’ queuing configuration everyone wants to get served at the same time and the influx should be managed with a set of distributed server.
Priority Queues: The priority queues are the most frequently used queuing discipline in the service industry, where different customer groups have different level of priority and everyone is served on the bases of their priority not their arrival.

It is crucial for a business to learn and understand the different queuing disciplines. As this will help them to set up their queuing environment and the specifications of the queue management system will be varied based on the required queuing disciplines.

The Measurements of the Queuing Theory

It is extremely difficult to explain the queuing theory to people without any understanding of the operational science. One must have scientific knowledge and understanding of various formulas to estimate the performance of the queuing system.

Here is the formula to calculate the performance of the queue management system:

L = λW

Where

L = Average Number of the Customers

λ = Average Arrival Rate of the Customer

W = Average Service Time for the Customers

This formula was proposed by Mr. John Little which is used to understand the relationship between the distribution rate of the customers and the time required by them to get served. However, the queuing process includes other important factors which can impact its performance:

Customer Arrival: The arrival rate of the customers who are positioned first in the waiting lines
System Capacity: It is the maximum capacity of the queue management system to handle the customers
Service Points: These are the service points where the service is delivered, it could be a single point service or a multi-step service which require arrival at one server and departure from a different server
Output: The output is the customers who are departing from the system after getting the service

There are several other more complex theoretical and mathematical models that are commonly used in by the operation researches in the queuing theory, such as David George Kendall’s queuing model, Hall’s Queuing Rule of Thumb, etc. but those would be too complex to discuss here. However, the important thing to understand is that applying queuing theory along with adequate mathematical models and simulations can greatly help improving your queue management system.

Conclusion

The queue management system is an integral part of a modern day service centers. Whether you are a small or large business your customer facing staff and channels should be equipped with the adequate technology and tools in order to make sure your customers have a satisfactory experience. The customer satisfaction is a key to long term success as it drives customer loyalty and help businesses sustain growth. Businesses in Dubai and all around the UAE are using digital queue management systems to improve their queuing processes. The modern day queue management systems are powered by AI (artificial intelligence) based algorithms which can dramatically improve the efficiency and performance of the queuing process.

However, when it comes to implement a queue management system businesses often don’t have a clue of what type of queuing process they need and what features could help them achieve their desired goals. The purpose of this blog was to introduce our audience with the queuing theory, explaining the queuing theory without the mathematical models and calculation is a herculean task for the operation researches or experts.

In this blog we have tried to simplify the queuing theory to make it digestible for ordinary audience and help them leverage it to design or chose the right queue management system for their needs. If you want to learn more about the subject or if you want our help to design a highly effective tailor-made queue management system for your business, please feel free to contact us through our Contact Us page or leave a comment in the comment box below and we will get in touch with you soon.

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