Homework answers / question archive / M454 Logistics Modelling Coursework 2 Due Date: 01 June 2022 (by 5:00pm) This coursework is worth 20% of the total module mark

M454 Logistics Modelling Coursework 2 Due Date: 01 June 2022 (by 5:00pm) This coursework is worth 20% of the total module mark

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M454 Logistics Modelling
Coursework 2
Due Date: 01 June 2022 (by 5:00pm)
This coursework is worth 20% of the total module mark. It is marked out of 88
marks.
Submission details:
1. Compile your solutions to Problem 1 and Problem 2 in a report, and submit it as
a softcopy to the module’s Moodle website. Your report must be typed and the font
size used must be 11 or greater.
2. Submit the SIMUL8 file from Problem 2, part b) in *.S8 format on the module‘s
Moodle website.
Please use your student ID number as your report and SIMUL8 (*.S8 format)
filenames (e.g. 2351363.S8).
Do not mention your name anywhere in your submissions.
This is an individual assignment. Plagiarism or copying is not permitted and any
offence will be dealt with under the University procedures.
Throughout this assignment please use the following constants:
u = The first two digits of your student ID number
v = The third and fourth digits of your student ID number
w = The fifth and sixth digits of your student ID number
(e.g. A student ID number 2351363 gives u = 23, v = 51, w = 36)
Problem 1
People arrive at a barbershop at the rate of one every 4.5 minutes. The shop can hold
up to four people waiting to be served in the FIFO manner for a haircut. If the shop is
full, 30% of the potential customers leave and come back in a time uniformly distributed
between 40 minutes and 80 minutes. The others leave and do not return. One barber
gives a haircut in a time uniformly distributed between 6 minutes and 10 minutes; the
second talks a lot and takes a time uniformly distributed between 8 minutes and 16
minutes. If both barbers are idle, a customer prefers the first barber. (Model customers
trying to reenter the shop as if they are new customers.) The system is simulated until
300 customers have received a haircut.
Using SIMUL8, perform 100 independent runs to determine the average number of
customers in the shop at any one time. Give your answer together with its low and
high 95% range as indicated in “Results Manager”. Describe as clearly as possible in
2
about 500 to 700 words how you build your model and determine the average number
of customers in the shop at a time. Screenshots and computer outputs should be
provided in your description, and a screenshot of your simulation model must be
provided. You do not need to submit the SIMUL8 file used to solve the problem. Use
the number v as your initial random seed.
[18 marks]
Problem 2
A bank with 4 tellers opens its doors at 9am and closes its doors at 5pm, but operates
until all customers in the bank by 5pm have been served. Assume that the interarrival
times of customers are independent and identically distributed that is exponential with
a mean of 1 minute, and that service times of customers are independent and
identically distributed that is exponential with a mean of 4.5 minutes.
Each teller has a separate queue. An arriving customer joins the shortest queue,
choosing an arbitrary shortest queue in case of ties. Queue discipline is FIFO. Now,
suppose that the bank’s lobby is large enough to hold only 25 customers in the queues
(total). If a customer arrives to find that there are already a total of 25 customers in
the queues, he or she just goes away and the business is lost; this is called balking
and is clearly unfortunate.
Problem Situation: The bank’s management is concerned with operating costs as
well as the quality of service currently being provided to customers, and is thinking of
changing the number of tellers. Changing the number of tellers by one saves/costs
the bank £8,000 per year, while management does not want a customer to wait too
long in a queue and also customers leaving without being served, hence affecting the
quality of service and incurring loss of goodwill.
a) Conceptual Model. Develop a conceptual model for the problem, by describing
the objectives, inputs, outputs, content (including a logic flow diagram),
assumptions and simplications of the model, in approximately 400 to 600 words.
[17 marks]
b) Computer Model. Build a computer simulation model in SIMUL8 to model the
system. A screenshot of your simulation model should be provided in your report.
Run the model independently 100 times to find

from the “Results Manager” in SIMUL8. Give your answers together with their low
and high 95% range as indicated in “Results Manager”. Use the number v as your
initial random seed.
[NOTE: You need to do some research to find suitable features in SIMUL8 not
taught in class to build your computer model. In particular, you need to find out
how to build your computer model such that it does not stop running after 8 hours
of simulation time, and such that it allows a maximum total of 25 customers and
not more queueing in all queues at any one time]
[28 marks]
3
c) Report to Manager. Write a report of approximately 1500 to 1800 words to the
system manager, explaining your recommendations to the problem situation
described above. Include the reasoning behind your choice and the comparative
advantages and disadvantages of your choice. Include graphs/tables to illustrate
and explain your recommendations. Remember that this report is for a business
manager and should hence be of high quality and not overly-technical.
[25 marks]
4
MARKING SCHEME
Problem 1
Accurate and detailed working process 15 marks
Correct answers 3 marks
Subtotal 18 marks
Problem 2
Part a): Conceptual Model
Development of conceptual model
• Objectives 2 marks
• Inputs 2 marks
• Outputs 2 marks
• Content 9 marks
• Assumptions 1 mark
• Simplications 1 mark
Subtotal 17 marks
Part b): Computer Model
Production of model
• Layout 3 marks
• Clarity 3 marks
• Accuracy 17 marks
Correct answers to questions 5 marks
Subtotal 28 marks
Part c): Production of Report
Reasoning and consideration of objectives 15 marks
Graphs and Illustrations 5 marks
Presentation 5 marks
Subtotal 25 marks