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Systems & Logistics Support Management

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MGT5061-FA21-A05 C2 RMA-beta

Florida Institute of Technology
Department of Extended Studies
Virtual Site

MGT5061-FA21 Systems & Logistics Support Management
Dr. Paul Battaglia

Assignment 05 C2 RMA BETA
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This case is 8 percent of the course grade
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Individual work.
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How submitted:
*** post your file (or files) with your answers to the assignment in Canvas.
**MS Word for longer narrative.
** If you use software (such as Excel), then also load that file.
** If you solve manually or graphically, then best to scan & load that file
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The general scenario is that you are working for the company (Light-Up-My-Light, Inc). And
need to do certain analytic or managerial work. Obviously (?), the major topics addressed will
be the course topics; and more specifically usually the material from the current chapters!

Please remember to:
.a. put your last name in the file name;

example: 5061-FA21-Battaglia-A05
.b. put your last name at the top of the first page of each file; and

something like 5061-FA21-Battaglia-A05
.c. number the pages.

I usually print out your answers and these items help me to identify whose work I am
looking at, grading, etc.

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Unless other arrangements are made (e.g., you “invoked” an extension), your answers are due
according to the class schedule.

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Basic Copyright 2021 Dr. Paul Battaglia and Florida Institute of Technology. For use ONLY in MGT5061 for the
FA21 term. Any other use requires explicit written permission.

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Light Up My Light, Inc.

Oh, oh!
The engineers are in a pinch. At the most recent staff meeting one pf the topics

discussed was that one of the newer light fixtures was having some problems. This is the
model L799AC. They are being returned at a rate that is much higher than anticipated. It
appears that the L799AC is just are not as durable as customers are expecting from a light
fixture. The planned MTBF was some 1,500 hours. The Operating time until failure for the
returned units ranged from 99 to 199 hours. That appears to be an eye-watering difference!

Customers and the LUML engineers know that there is a “mixture” of factors (e.g.,
reliability; maintainability even though is most cases customers plan on doing very little
maintenance beyond changing the bulb once the fixture is installed; and availability).

The CEO asked them to look into this situation, and to send her a memo on the
situation.

Alas, the engineers are not always agreeing on what the situation is or how to
proceed. With somewhat bruised egos, then have asked your boss Tom Perkins (VP/Director
of Logistics) for assistance in analyzing the situation and drafting the memo to reply to the
CEO.

Perkins said sure; go ahead and coordinate with {your name}.

Here are the “issues” that they need help with.

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Q#1. (100 points) The idea of a “bathtub” is often used to describe the failure rate curve.
When searching the Internet and other sources (some old textbooks) they got a zillion hits
(or at least a very large number). But what they need is a concise answer to explain this

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concept to the non-engineer, non-logistician CEO. Probably a figure. And then a brief
explanation of the elapsed time and the failure rate. A time period/region (or is that
periods/regions?). And the characteristics of each period/region that the curve covers.

Q#2. (100 points) Luckily several customers kept records on failure of the fixtures. Here is
a summary of the 8 units returned due to failure.

Returned
Unit #

Operating time until failed
(hours)

1 133
2 155
3 199
4 176
5 148
6 165
7 160
8 99

[NOTE: This is obviously a small sample of 8 observations. But treat this as if it
represented a very large sample so, for example, you do not need to try to apply a finite
population correction factor, etc.]

Q#2a. If the returned fixtures were in the stage where the exponential reliability
function applied, based on these actual MTBF’s what was the theoretical reliability at 200
hours of operation? [Note: to 2 decimal places.]

Q#2B. Show your work and explain your answer.

Q#3. (100 points) The fixture has three major components which act in series. [Note: final
answers to 2 decimal places.]

Part #1 has a reliability of 0.99.
Part #2 has a reliability of 0.97.
Part #3 has a reliability of 0.90.

Q#3a. What is the theoretical reliability of the system/product?

Q#3b. If LUML is going to work on improving the reliability of the system/product,
which part do you recommend the engineers initially concentrate on? Why?

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Q#3c. If LUML can improve the reliability of that part by 5 per cent, what should the
new reliability be for the system/product?

Q#4. (100 points) The planned MTBF was 1,550 hours. The average corrective maintenance
time was planned to be 1 hour. [Note: satisfactory conditions, etc., etc.]

Q#4a. What was the planned inherent availability of the system/product?
Q#4b. Explain your work and the implications for LUML.

Q#5. (50 points) One aspect of MGT5061 is to address “policy”. Give and explain two policies
concerning RMA that LUML should consider implementing. Include the reason(s) why the
policy would be appropriate? (Or, if you prefer, consider it RAM knowing RAM distorts the
relationship to some degree.)

No real limits on length. On the one hand, I am not looking for multiple pages. On the
other hand, you do need to cover the topic. Usually a few sentences with solid reasons for
each is sufficient.

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Reminder. There are graded elements that are not always explicitly stated.

For example, use of sources to document ideas that are not your own. In the text and a
reference list.

Note that even in “real life” my experience is that you should have
the “backup” that you need just-in-case-you-are-asked. The
difference is probably more of the formality of documenting your
sources rather than “should I have backup?”.

It is usually a very good idea to explain why the person is getting this document (aka
purpose?).