06 ICA - Modeling & Design
docx
keyboard_arrow_up
School
Wake Tech *
*We aren’t endorsed by this school
Course
143
Subject
Industrial Engineering
Date
Jan 9, 2024
Type
docx
Pages
2
Uploaded by bellaangarone
Simulation Modeling and Experimental Design Assignment
The Hungarian/Greek fusion burritos truck has decided to do a more complete simulation.
Interarrival Times: you estimated customers arrive in a uniform distribution with a minimum of 0
seconds and a maximum of 30 seconds between customers.
To simulate a uniform distribution,
simply multiply the random number by the range (maximum minus minimum) and add that to
the minimum.
Service Times: you estimated the service time as an exponential distribution with a mean of 45
seconds.
Remember that the inverse formula for the exponential distribution is the natural log
(=LN).
Take the natural log of the random number and multiply that by the mean of the
distribution, remembering to make the whole thing negative.
Use the spreadsheet you built before, but add a column after the interarrival random times to
calculate the arrival time (previous arrival time + current interarrival time).
Use the Service
random values as the service times for each customer.
Determine the Start-of-Service time
(greater of the previous customer’s end-of-service time and the current customer’s arrival time)
and End-of-Service time (Start-of-Service time + Service Time) for each customer.
For output, calculate the Wait Times (in minutes) for each customer (Start-of-Service minus
Arrival) and the average wait time for the 90 customers.
Also find the maximum wait, and the
number of customers waiting less than 1 minute, between 1 and 5 minutes, and greater than 10
minutes (use the COUNTIF function).
Create a data table that does 50 replications of the
simulation for all those outputs.
Average the 50 replications.
Determine a 95% confidence
interval for the average wait time.
Do all of this before considering the What-If scenarios below.
You should end up with a spreadsheet that looks very much like the lecture note and example
spreadsheets.
Now, create a copy of the simulation spreadsheet and copy the random numbers provided in
Canvas (“Assignment Random Numbers”) in place of the “=RAND()” functions (both columns).
That way, you all have the same output, but it makes the Data Table and Confidence Interval tabs
irrelevant.
For the “What-If Scenarios”, make copies of the Simulation tab using the “fixed”
values for the random numbers, and change the parameters one at a time.
Do not combine the
scenarios – each one is entirely separate from the others.
What-If Scenarios
Raising your prices would decrease the number of customers you have.
Change the
maximum arrival time from 30 to 40, and delete the last 10 customers (change the
number of customers from 90 to 80).
Options for reducing the service time are:
o
Decrease options (reduce mean service time from 45 seconds to 35 seconds)
o
Hire an assistant (reduce mean service time from 45 seconds to 25 seconds)
o
Prepare foods in advance instead of making fresh (reduce mean service time
from 45 seconds to 30 seconds)
Answer these questions:
1)
Explain to your boss the logic of the Start-of-Service calculation
2)
Why don’t the Wait Times (<1, 1 to 5, and >10) add up to 90 (or 80 for the first
scenario)?
3)
Using the Wait Time numbers (<1 1 to 5, >10) describe the effects of the various
scenarios
4)
What scenario was not explored that would make sense to look at?
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help