queuingtheory

1. ““QUEUING THEORY”QUEUING THEORY”
Presented By–Presented By– ROHIT PATELROHIT PATEL
M.PHARM+MBA (QA-003)M.PHARM+MBA (QA-003)

2. Queuing TheoryQueuing Theory

Queuing theory is the mathematics of waiting lines.Queuing theory is the mathematics of waiting lines.
 It is extremely useful in predicting and evaluatingIt is extremely useful in predicting and evaluating
system performance.system performance.
 Queuing theory has been used for operationsQueuing theory has been used for operations
research, manufacturing and systems analysis.research, manufacturing and systems analysis.
Traditional queuing theory problems refer toTraditional queuing theory problems refer to
customers visiting a store, analogous to requestscustomers visiting a store, analogous to requests
arriving at a device.arriving at a device.

3. Applications of Queuing TheoryApplications of Queuing Theory
 TelecommunicationsTelecommunications
 Traffic controlTraffic control
 Determining the sequence of computerDetermining the sequence of computer
operationsoperations
 Predicting computer performancePredicting computer performance
 Health services (e.g.. control of hospital bedHealth services (e.g.. control of hospital bed
assignments)assignments)
 Airport traffic, airline ticket salesAirport traffic, airline ticket sales
 Layout of manufacturing systems.Layout of manufacturing systems.

4. Queuing SystemQueuing System
 Model processes in which customers arrive.Model processes in which customers arrive.
 Wait their turn for service.Wait their turn for service.
 Are serviced and then leave.Are serviced and then leave.
input
Server
Queue
output

5. Characteristics of Queuing
Systems
 Key elementsKey elements of queuing systemsof queuing systems
•• Customer:--Customer:-- refers to anything that arrives at a facilityrefers to anything that arrives at a facility
and requires service, e.g., people, machines, trucks,and requires service, e.g., people, machines, trucks,
emails.emails.
•• Server:--Server:-- refers to any resource that provides therefers to any resource that provides the
requested service, eg. repairpersons, retrieval machines,requested service, eg. repairpersons, retrieval machines,
runways at airport.runways at airport.

6. System Customers Server
Reception desk People Receptionist
Hospital Patients Nurses
Airport Airplanes Runway
Road network Cars Traffic light
Grocery Shoppers Checkout
station
Computer Jobs CPU, disk, CD
Queuing examplesQueuing examples

7. Components of a Queuing SystemComponents of a Queuing System
Arrival Process
Servers
Queue or
Waiting Line
Service Process
Exit

8. Parts of a Waiting LineParts of a Waiting Line
Dave’sDave’s
Car WashCar Wash
enterenter exitexit
Population ofPopulation of
dirty carsdirty cars
ArrivalsArrivals
from thefrom the
generalgeneral
population …population …
QueueQueue
(waiting line)(waiting line)
ServiceService
facilityfacility
Exit the systemExit the system
Exit the systemExit the systemArrivals processArrivals process Queue structureQueue structure

9. 1.1. Arrival ProcessArrival Process
 According to sourceAccording to source
 According to numbersAccording to numbers
 According to timeAccording to time
2. Queue Structure
• First-come-first-served (FCFS)
• Last-come-first-serve (LCFS)
• Service-in-random-order (SIRO)
• Priority service

10. 3.3. Service systemService system
1.1. A single service system.A single service system.
Queue
ArrivalsArrivals
Service
facility
DeparturesDepartures
after serviceafter service
e.g- Your family dentist’s office, Library countere.g- Your family dentist’s office, Library counter

11. 2. Multiple, parallel server, single2. Multiple, parallel server, single
queue modelqueue model
Queue
Service
facility
Channel 1
Service
facility
Channel 2
Service
facility
Channel 3
ArrivalsArrivals
DeparturesDepartures
after serviceafter service
e.g- Booking at a service statione.g- Booking at a service station

12. 3. Multiple, parallel facilities with3. Multiple, parallel facilities with
multiple queues Modelmultiple queues Model
Service station Customers
leave
Queues
Arrivals
e.g.- Different cash counters in electricity office

13. 4. Service facilities in a series4. Service facilities in a series
Arrivals
Queues
Service station 1 Service station 2
Queues
Customers
leave
Phase 1 Phase 2
e.g.- Cutting, turning, knurling, drilling, grinding,
packaging operation of steel

15. Irisys Queue ManagementIrisys Queue Management‫׃‬‫׃‬ Tesco supermarketTesco supermarket
case studycase study

16. Thank youThank you