CSC 222: Computer Programming II
Spring 2004
HW5: Queues and Simulation
For this assignment, you are to complete the bank simulation project, which uses a
queue to
simulate customers arriving and being served in a small bank.
Recall the following assumptions:
- There is only one teller, and customers are served on a first-come-first-served
basis.
- At any given minute of the day, there is a fixed probability of a
customer arriving at the bank. For example, if the arrival probability is 15, then
there is a 15% chance
that a customer will arrive at any given minute.
- The length of the transaction for a given customer, in minutes, is a random integer
between 1 and some fixed constant (initially set to 8 minutes).
The following files have been
provided for you: Customer.h, Customer.cpp, Teller.h,
Teller.cpp, Die.h, Die.cpp, ServiceCenter.hand banksim.cpp.
Part 1: Implementing ServiceCenter
To complete the simulation, you are to implement the ServiceCenter class.
An object of this class
contains a single Teller object for serving customers, and a queue of customers
waiting to be served. The
addCustomer member function should create a new customer, add them to the
waiting queue, and display
information about the customer. The serveCustomers member function should
perform a step in the
simulation, checking to see if the teller has finished with a customer and, if so,
whether a new customer can be
served. It should also display a message if the teller finishes or begins serving a
customer.
For example, the output of the simulation should look like the following:
<![CDATA[
What is the time duration (in minutes) to be simulated? 10
What percentage of the time (0-100) does a customer arrive? 30
2: Adding customer 1 (job length = 4)
2: Serving customer 1 (finish at 6)
4: Adding customer 2 (job length = 3)
5: Adding customer 3 (job length = 1)
6: Finished customer 1
6: Serving customer 2 (finish at 9)
9: Adding customer 4 (job length = 3)
9: Finished customer 2
9: Serving customer 3 (finish at 10)
10: Finished customer 3
10: Serving customer 4 (finish at 13)
13: Finished customer 4
]]>
Part 2: Maintaining Statistics
Once you have the simulation working correctly, add a member function named
DisplayStats that displays
statistics on the simulation. You should modify the ServiceCenter class so
that an object keeps track of:
- the number of customers whose jobs have been completed,
- the average waiting time for all customers whose jobs have been completed, and
- the longest waiting time for any customer.
The DisplayStats member function, when called, should display these
statistics in a readable form. Add
a call to the banksim.cpp program so that DisplayStats is called at
the end of the simulation to
display statistics.
Part 3: Analysis
Once you have your bank simulation program working, answer these questions:
- Assuming a banking day of 8 hours (240 minutes), how many customers would you expect
to
serve if the arrival probability were 20%. Do your simulations support this answer?
- Assuming a banking day of 8 hours and an arrival probability of 15%, what is the
average
wait time for customers at the bank. Run several simulations and comment on the
consistency of
the results.
- Assuming a banking day of 8 hours, what arrival probability can the bank handle and
still
keep the maximum wait time for customers under 10 minutes. Explain how you came up with
this
number.