Page 224 - DCOM303_DMGT504_OPERATION_RESEARCH

Unit 11: Queuing Theory

Reneging: Customer after joining the queue, waits for some time and leaves the service system Notes
due to delay in service.
Jockeying: Customer moves from one queue to another thinking that he will get served faster
by doing so.

Self Assessment

Multiple Choice Questions:
1. Which of the following characteristics apply to queueing system

(a) Customer perception (b) Arrival process
(c) Both a and b (d) none of the above
2. The cost of providing service in a queueing system decreases with
(a) Decreased average waiting time in a queue
(b) Decreased arrival time

(c) Increased arrival rate
(d) None of the above
3. Priority queue discipline may be classified as

(a) Finite or infinite (b) Limited or unlimited
(c) Preemptive or non preemptive (d) All of the above

11.2 Waiting Line Process

Waiting in lines is a part of our everyday life. Waiting in lines may be due to overcrowded,
overfilling or due to congestion. Any time there is more customer demand for a service than can
be provided, a waiting line forms. We wait in lines at the movie theater, at the bank for a teller,
at a grocery store. Wait time depends on the number of people waiting before you, the number
of servers serving line, and the amount of service time for each individual customer. Customers
can be either humans or an object such as customer orders to be process, a machine waiting for
repair. Mathematical analytical method of analyzing the relationship between congestion and
delay caused by it can be modeled using Queuing analysis.
A waiting line process or queuing process is defined by two important elements:
 the population source of its customers and

 the process or service system.
The customer population can be considered as finite or infinite. The customer population is
finite when the number of customers affects potential new customers for the service system
already in the system. When the number of customers waiting in line does not significantly
affect the rate at which the population generates new customers, the customer population is
considered infinite. Customer behavior can change and depends on waiting line characteristics.
In addition to waiting, a customer can choose other alternative.
When customer enters the waiting line but leaves before being serviced, process is called Reneging.

When customer changes one line to another to reduce wait time, process is called Jockeying.
Balking occurs when customer do not enter waiting line but decides to come back latter.

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