CS233 Data Structures and Analysis of Algorithms II
Assignment 3
Spring 2002

The purpose of this assignment is to continue our study of discrete event simulation by enhancing the bank teller simulation program  you modified in assignment 2.

Part 1 - Single Q, Single Teller
The program, as you modified,  only prints the average wait time and the number of customers that left the bank.  You are to modify the program to print the following statistics as well

Run the program for a simulation time of 500 minutes for a single teller and a maximum service time of 5 minutes.  Complete the following table.
 
Possibility of Customer Arrival            10%            20%           30%           40%
Max Q Length        
Min/Max/Avg Service Time        
Avg. Wait Time        
Teller Utilization        
Min/Max/Avg. Time in Bank        
Number customers that entered bank        
Number of customers that left bank        

 

Part 2 - One Queue per Teller, and One Queue for all 3 Tellers
In part two you will study the effect of having one queue for all tellers verses one queue for each teller. Modify the program to have one queue for each teller.  When a customer enters the bank the customer should be placed in the shortest queue.  Each teller services customers only from the corresponding queue and not other teller's queue.

Complete additional tables (like the one in part 1) for  three tellers. One table for one queue per system.

Data for Three Tellers and One Queue Per Bank


Possibility of Customer Arrival    10%       20%    30%       40%      50%     60%   70%   80%   90%
Max Q Length                
Min/Max/Avg Service Time                  
Avg. Wait Time                  
Teller 1 Utilization                  
Teller 2 Utilization                  
Teller 3 Utilization                  
Min/Max/Avg. Time in Bank                  
Number customers that entered bank                  
Number of customers that left bank                  

 
 
 

Data for Three Tellers and Three Queues


Possibility of Customer Arrival    10%      20%    30%       40%      50%     60%   70%   80%   90%
Max Q Length Teller 1                  
Max Q Length Teller 2                  
Max Q Length Teller 3                  
Min/Max/Avg Service Time                  
Avg. Wait Time                  
Teller 1 Utilization                  
Teller 2 Utilization                  
Teller 3 Utilization                  
Min/Max/Avg. Time in Bank                  
Number customers that entered bank                  
Number of customers that left bank                  

 

Since there are three tellers the bank can handle many more customers than with one teller, hence the arrival rate can be much higher.  Try varying  the possibility of customer arrival up to 90%, keeping the simulation time of 500 minutes and customer processing time of 5 minutes constant.  The system may become unstable (queue length and average wait time go up dramatically before you reach 90%).  Plot, on one graph, two curves of average wait time Vs customer arrival percent for 3 tellers - one curve for one queue per teller and one curve for one queue for the entire bank.

Which configuration of the bank results in lower average customer wait time?
 
 

Due March 22nd