Queing model

Queing Model or Waiting line theory was developed by A.K.Erlang in 1903. He used this model to solve the problem of congestion in telephone traffic.

Waiting lines or queues are present everywhere. All businesses such as manufacturing industries, schools, hospitals, banks, postal offices- all have queues

Waiting line problem arises because-
1) There is too much of waiting time i.e. there is inadequate service facility.
2) There is too less demand i.e. there is too much of idle service facility
In both cases there is a loss to company so company tries to obtain a balance between the cost associated with waiting line and idle service facility.

Elements of queuing systems:
Customer - Arriving unit that requires some service
Queue - The number of customers waiting to be served. This does not include customers which are being served.
Service Channel – The system performing service to the customers.

Characteristic of Queuing models
1. Input or arrival distribution
2. Output or departure distribution
3. Service channel
4. Service Discipline
5. Maximum number of customer allowed in the system
6. Calling source or population

Objective of Queuing theory is to minimize the total cost of providing service and waiting in the line.