MGT 560 Queuing System Simulation Stochastic Modeling © Victor E. Sower, Ph.D., C.Q.E. 2007.

MGT 560Queuing System Simulation

Stochastic Modeling

© Victor E. Sower, Ph.D., C.Q.E. 2007

Steps in Simulation Process

1. Define problem2. Define important variables in problem3. Collect data4. Construct mathematical model5. Validate model6. Define experiments to run7. Run experiments8. Consider results (possible model modification)9. Decide on course of action

Victor E. Sower, Ph.D., C.Q.E. 2007

Advantages of Simulation

• Straightforward and flexible• Can analyze complex real-world situations• Can use any distributions—not just standard ones• Time compression• Can address “what-if” questions• Off-line• Can study interactions of individual variables and

components


Limitations of Simulation

• Expensive and time consuming• Does not generate optimal solutions• The results from the model are limited by the

quality of the design of the model• Each simulation model is unique to a particular

problem


Types of Queuing Systems

Single channel; Single phase


Channel – the number of parallel servers

Phase – the number of servers in sequence


Multiple channel; Single phase



Single channel/Multiple phase



Multiple channel/Multiple phase


Data Collection

• Source of customers– Infinite– Finite


Data Collection

• Arrival Rate/Interarrival Time– Arrival Rate (Poisson)– Interarrival Time (Exponential)


Data Collection

• Service Rate/Service Time– Service Rate (Poisson)– Service Time (Exponential)


Data Collection• Queue Discipline– FCFS– LIFO– Random– Others


Data Collection

• Queue Length– Infinite– Finite• Balking


System Operating CharacteristicsResults from Model

• L Avg. no. of customers in system• Lq Avg. no. of customers in the queue• W Avg. time customer spends in system• Wq Avg. time customer spends in queue• p Utilization rate


System Considerations

• Waiting line costs• Service quality• Psychology of waiting• Balking


MGT 560 Queuing System Simulation Stochastic Modeling © Victor E. Sower, Ph.D., C.Q.E. 2007.

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