MOS 3330 Final Review Problem

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MOS 3330 Final Exam
Review Problems & Solutions
General Information
Course grade distribution policy:
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DAN Management 3000 & 4000 level courses: Mean of between 70-77% for all sections of the
same course taught by the same instructor in that semester
Exam date, time, location:
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See the course outline
See also the course web site: dan.uwo.ca/courses/3330
Exam conflict consists of having 3 exams within 23 hours
Missing the test – check the course web site for instruction
Exam coverage:
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•
•
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Final exam is not cumulative of Test 1 and Test 2 materials.
Topics covered in the final exam:
o Process and product design
o JIT systems
o Quality
o SPC
o TQM
Final exam covers all materials covered in the lecture slide book for the topics mentioned above
Materials that are in the textbook but NOT in the lecture slide book will NOT be on the test.
Therefore, you do not have to memorize everything in the textbook; in the textbook, read only
the same materials covered in the lecture slide book.
Exam structure:
•
•
Final exam is worth 30% of your course grade
Final exam = total 65 marks
o Question 1 – Computational, 2 parts, total 16 marks
o Question 2 – Short answers, 1 question (conceptual, no calculation), total 9 marks
o Question 3 – Multiple choice, 40 questions (concepts and simple calculations), 1 mark each,
total 40 marks
o Formula sheet – provided on the last page of the exam (same from Test 1 & Test 2)
Don’t forget to bring to test:
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•
•
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Student ID
Non-programmable calculator
Pencils
Ruler
No cell phones on person or on desk during the test
No personal scrap paper
1
A. Computational
General Tips
Recommended steps for how to prepare for computational questions in Final Exam:
1. Review computational examples in the lecture notes.
− Familiarize yourself with the format of a SPC chart; the exam will provide a grid but
nothing else
− Understand how to calculate the center, UCL, and LCL
− Understand what values to plot on a chart.
− Understand how to make a conclusion about the process in question.
− Understand the differences among 4 types of SPC charts; you have to determine
which one to use based on the data, context, and what the question is asking for.
2. Download the formula sheet from the course web site.
− Final exam covers the last ¹∕₃ of the formula sheet.
− Symbols are not defined on the formula sheet; you should know what they stand for.
3. Study end-of-chapter problems in the textbook.
− See A1.
4. Study questions from the old exams.
− See A2.
Rounding Reminder
•
For SPC questions, keep 2 or 3 decimal points throughout.
A1. Textbook Computational Problems
Topic
SPC
Suggested textbook end-of-chapter problems
#3 – in the textbook answer, only x-bar chart is shown → in the final exam, both x-bar and
R charts should be done
#5 – in the textbook answer, only R chart is shown → in the final exam, both x-bar and R
charts should be done
#6
#7
#8
#9
2
A2. Computational Questions from Old Exams
1. The Northern Outdoors Clothing Company, a mail-order catalogue operation based in Brampton,
Ontario, contracts with the Federal Parcel Service (FPS) to deliver all of its orders to customers.
Northern tells its customers it will deliver their order (if the items are in stock) within 3 business days
anywhere in Ontario.
a) As part of its TQM program, Northern has started tracking the delivery time for some of its orders.
The following table shows seven samples of randomly selected orders. Northern at this point claims
that it only cares about whether or not the order is delivered on time. Construct an appropriate
control chart(s) to monitor FPS delivery quality using 3 sigma limits. Show clearly on the graph the
values for the center line, UCL and LCL. Is the process in control? Justify your answer briefly.
Sample
Delivery time (in days)
1
2
4
3
4
3
2
3
1
2
3
3
4
4
1
1
2
6
3
4
3
4
6
2
5
4
2
4
1
1
5
3
4
5
3
2
5
4
4
1
4
4
4
5
4
6
4
4
4
2
4
5
3
4
7
1
2
4
3
5
4
5
3
b) The table below shows two additional samples. Should you be concerned about the delivery
process? Justify your answer based on the chart(s) you already constructed in part a) (i.e., for
this question, use the same center line, UCL and LCL that were used in part a).
Sample
Delivery time (in days)
8
6
3
3
3
5
3
1
2
9
6
4
4
3
5
4
5
4
c) Is the control chart(s) constructed in part a) a good choice of monitoring delivery quality? Justify
your answer briefly.
2. The North Country Clothing Company (NCCC) is a mail-order company that processes thousands of
mail and telephone orders each week. They have a customer service number to handle customer order
problems and monitor the number of complaints. The total number of complaint calls the customer
service department has received for each of the last 30 weeks are shown below. The average number of
complaints has been 24 in the past year. Construct an appropriate control chart(s) to monitor customer
service quality using 3 sigma limits. Show clearly on the graph the values for the center line, UCL and
LCL. Is the process in control? Justify your answer briefly.
Week
1
2
3
4
5
6
7
8
9
10
No. of Complaints
27
15
36
28
19
23
21
16
29
35
Week
11
12
13
14
15
16
17
18
19
20
No. of Complaints
26
30
33
35
25
19
12
17
18
26
Week
21
22
23
24
25
26
27
28
29
30
No. of Complaints
31
14
18
26
27
30
20
12
16
20
3
3. A call centre monitors the number of customer calls that can be classified as complaints. A part of SPC
chart that keeps track of the number of complaints is shown below. The sample average is 3.7, UCL is
9.5 and LCL is 0. Suggest any corrective actions as you see fit.
10
9
8
7
6
5
4
3
2
1
0
1
3
5
7
9
11
4
B. Multiple Choice
General Tips
Recommended steps for how to prepare for multiple choice questions in Final Exam:
1. Focus on the lecture slide book.
− Know details → be able to define/explain all terms & concepts in the lecture notes.
− If you are not sure about a term or concept, make a note of that and look it up in the
textbook later (see Step 3).
2. Read the textbook chapters that correspond to the test coverage.
− DO NOT read the textbook unless you are clear about what is in the lecture notes.
− Take notes only on the materials covered in the lecture notes.
− Take notes on terms/concepts that you were not sure about in the lecture notes.
− Read quickly through the terms/concepts that are not in the lecture notes (don’t
take any notes).
− Generally, you can find the materials covered in the lecture notes in the following
chapters/pages: Chapter 3 (pp. 54-97), Chapter 7 (pp. 234-266), Chapter 5 (pp. 151170-184), and Chapter 6 (pp. 185-305, 208-211, 216-233)
3. Study questions from the old exams.
− See B1 below.
B1. Multiple Choice Questions from Old Exams
1) An advantage of the batch production process is
a. low production cost
b. total customization
c. efficiency
d. variety
2) All of the following are critical input to JIT production except
a. steady production
b. flexible workforce
c. small inventory
d. extremely high quality
3) A producer would most likely view quality as
a. quality of design
b. meeting requirements
c. fitness for use
d. meeting or exceeding customer expectations
4) ISO 9000 certification
a. aims to promote top management’s commitment to TQM
b. certifies products and their manufacturing processes
c. does not apply to service industries
d. is seen as a customer requirement
5
5) SPC
a. eliminates poor quality
b. measures process variability
c. measures product specifications
d. identifies quality problems
6) Since the advent of JIT, many suppliers
a. relocated to China
b. ask their customers to be quality certified
c. use smaller trucks more frequently
d. ask their customers to reduce product specifications
7) Which one of the following statement about quality management is true?
a. Internal failure due to poor quality has no effect on production lead time or delivery time.
b. Reducing internal failure results in less loss of material or machine capacity.
c. Since external failures occur outside the plant, operations cannot do anything to minimize them.
d. As the quality level of a process increases, appraisal costs will go up due to increased testing effort.
8) From a restaurant chain’s (e.g., McDonald’s) perspective, the fast-food restaurant operation is an
example of
a. job shop production
b. continuous production
c. batch production
d. mass production
9) Process capability
a. can be measured with UCL and LCL
b. should always have a larger sigma limit than that of design specifications
c. that does not meet design specifications has a narrower range between UTL and LTL than a range
between UCL and LCL
d. that meets and exceeds design specifications has a wider range between UCL and LCL than a range
between UTL and LTL
10) Which is a likely result of TQM?
a. decreased product inspection
b. bottom-line approach
c. breakthrough improvements
d. top management with strong leadership and complete authority
11) Which of the following process is considered as a project?
a. picking grapes
b. designing a bridge
c. car assembly
d. producing sugar
12) Uniform loading
a. deals with supply variability
b. results in maintaining inventory of one or two main products
c. implies steady demand of finished products
d. may lead to a routine work for employees on the assembly line
13) TQM seeks ultimately to
a. eliminate costs of poor quality
b. eliminate all quality-related costs
c. reduce costs of poor quality
d. reduce costs of good quality
6
14) A manager of a café hears complaints here and there from the customers about the new line of cheese
cakes, but is not quite sure what’s going on. Which process improvement tool could help the manager
identify possible quality problems?
a. x-bar-chart
b. Check sheet
c. Scatter diagram
d. Fishbone diagram
15) Compared to the sigma limit of 3, having the sigma limit of 2 in SPC would more likely lead to
a. reduction of the size of abnormal variations
b. a conclusion that the process is in control when it is not
c. a conclusion that the process capability cannot meet design specifications
d. a conclusion that the process is out of control when it is not
16) Highly-skilled hourly workers would be most needed in
a. batch production
b. continuous production
c. mass production
d. automated production
17) A company with a pure continuous processing system is most likely to use which layout type?
a. Hybrid layout
b. Process layout
c. Product layout
d. Fixed position
18) A manufacturing company has a weekly product rate of 1700 units. The average percentage of goodquality products is 83%. Of the poor-quality products, 60% can be reworked and sold as good-quality
products. What is the weekly product yield?
a. 1445
b. 2465
c. 1020
d. 1584
19) The philosophy of zero defects is
a. consistent with the commitment to continuous improvement
b. prohibitively costly
c. unrealistic
d. impossible
20) Which of the following is an advantage of specialization in job design?
a. High turnover rates
b. Minimal training needs
c. Intrinsic satisfaction of employees
d. Increased opportunity for advancement of employees
21) Which of the following statements regarding a pull system is true?
a. Large lots are pulled from form upstream.
b. Each workstation requests items from previous workstation when needed.
c. Each workstation produces according to a schedule.
d. Work is pulled to the downstream station before it is needed.
22) For which of the following would a control chart for attributes not be appropriate?
a. Number of rotten apples
b. Proportion of broken eggs in a carton
c. Number of customer complaints
d. Length of metal rods being produced
7
23) Company Q’s quality cost was $52,000 and production cost was $274,000 last year. This year quality
cost is expected to be $54,000 and production cost to be $288,000. What is the cost index for this year,
and did quality improve from last year to this year?
a. cost index is 0.1875; quality is about the same
b. cost index is 0.1875; quality is definitely worse
c. cost index is 0.1898; quality is about the same
d. cost index is 0.1898; quality is definitely better
24) Which quality award is the oldest?
a. Deming Prize
b. Canada Awards for Excellence
c. Baldrige Award
d. European Quality Award
25) What is the approach to eliminating employee boredom by increasing the number of related tasks in a
specialized job?
a. job rotation
b. job specialization
c. job enlargement
d. job enhancement
8
C. Short Answers
General Tips
Recommended steps for how to prepare for short answer questions in Final Exam:
1. Study the lecture slide book.
− Know details → be able to define/explain all terms & concepts in the lecture notes.
− If you study the lecture notes for multiple choice questions, then you are studying
for short answers at the same time.
2. Read the textbook chapters that correspond to the new materials.
− DO NOT read the textbook unless you are clear about what is in the lecture notes.
− Take notes only on the materials covered in the lecture notes.
− Take notes on different examples and alternate explanations.
− In regard to the terms/concepts that are not in the lecture notes but are in the
textbook, reading through them once is recommended because it provides you with
a broad perspective, which is helpful for building your justification.
− Generally, you can find the materials covered in the lecture notes in the following
chapters/pages: Chapter 3 (pp. 54-97), Chapter 7 (pp. 234-266), Chapter 5 (pp. 151170-184), and Chapter 6 (pp. 185-305, 208-211, 216-233)
3. Study end-of-chapter discussion questions from the textbook.
− See C1 below.
4. Study questions from the old exams.
− See C2 below.
A short answer question may be about:
• Application of a concept to a real-world setting
• Suitability of a strategy/method/model for a particular organization
• Choice of strategies/methods/models for a particular organization
• Improvement suggestions for various operational issues
• Real-world examples of a concept
Do’s and Don’ts:
• Do demonstrate the basic understanding of concepts covered in the course.
• Do provide a sound and comprehensive justification/explanation that fits the context of the
question.
• Do answer the question as directly as possible.
• Don’t include irrelevant ideas.
• Don’t go off at a tangent.
• Don’t repeat/rephrase the same points.
9
C1. Textbook Discussion Questions
Topic
Process Design
JIT Systems
TQM
SPC
Suggested end-of-chapter discussion questions
#7, 10 + Case: Biddy’s Bakery #3
#1, 3, 4, 5, 7, 10 + Case: Dixon #1, 2
#1, 2, 3, 6, 7, 8, 10, 11, 12 + Case: GCA #1
#4, 5, 6, 7, 8, 9
C2. Short Answer Questions from Old Exams
1. Describe how the quality of facial tissue paper can be defined in operations and give some examples of
the quality measures that can be used to assess the tissue paper’s quality. If Kleenex (a major
manufacturer of facial tissue products in North America) were to launch a new advertising campaign
that emphasizes “improved quality,” which quality definition would be useful for Kleenex?
2. Which process type is most suitable for planning an Olympic game? Justify your answer briefly.
3. Is the JIT system suitable for all companies? Explain your answer briefly.
4. Discuss how a JIT system contributes to quality improvement.
5. An automotive-part manufacturer started using kanbans two months ago in its effort to become a “justin-time” company. The company expected to see some reduction in its inventory by now, but the level
of inventory has not gone down at all. Speculate as to why the inventory level has not changed at this
manufacturing plant.
6. If you were in charge of a startup company with shipping service as the core business, how would you
implement the philosophy of TQM?
7. Explain why TQM may be difficult to achieve in a short period of time for a company that has placed a
low priority on the quality initiatives over the years.
10
Solutions
A1. Textbook Computational Problems
SPC, #3
SPC, #5
SPC, #6
SPC, #7
SPC, #8
SPC, #9
Appendix A (look for chapter 6 answers)
Appendix A (look for chapter 6 answers)
(a) x-bar chart: center = 12.00, UCL = 12.00 + (0.48)(0.60) = 12.29, LCL = 12.00 –
(0.48)(0.60) = 11.71; R chart: center = 0.60, UCL = (2.0)(0.60) = 1.20, LCL = (0)(0.6) = 0
(b) R-chart is in control, but since x-bar chart is not in control, then the process is not in
control
Appendix A (look for chapter 6 answers)
(a) center = 18/200 = 0.09, UCL = 0.09 + 3(0.064) = 0.282, LCL = 0.09 – 3(0.064) = –0.102
⇒0
(b) process is out of control
Appendix A (look for chapter 6 answers)
A2. Computational Questions from Old Exams
1. a) Northern only cares about whether or not the order is delivered on time
⇒ defective vs. non-defective
We can count the number of “non-defective” delivery time; a sample is not “one item”, it consists of
8 delivery time observations ⇒ construct a p-chart
Sample
1
2
3
4
5
6
7
2
3
4
1
4
4
1
4
3
3
1
4
4
2
Delivery time (in days)
3
4
3
2
4
4
1
1
4
6
2
5
5
3
4
5
1
4
4
4
4
2
4
5
4
3
5
4
3
2
4
3
5
3
5
p = % defects
2/8 = 0.250
3/8 = 0.375
5/8 = 0.625
3/8 = 0.375
7/8 = 0.875
6/8 = 0.750
4/8 = 0.500
1
6
2
2
4
4
3
Center line = (0.25 + 0.375 + 0.625 + 0.375 + 0.875 + 0.75 + 0.5)/7 = 0.536
UCL = pavg + z[pavg(1 – pavg)/n]1/2 = 0.536 + (3)[(0.536)(0.464)/8]1/2 = 0.536 + 0.529 = 1.065
LCL = pavg – z[pavg(1 – pavg)/n]1/2 = 0.536 – 0.529 = 0.007
1.2
1
0.8
0.6
0.4
0.2
0
1
2
3
4
5
6
7
8
9
11
Note: the chart shows solutions for parts a) and b), including zones for patterns #4&5.
No sample points are outside the control limits; most points are near the centre line; about equal
number of points above (3) and below (4) the center line; points appear randomly distributed; for
the first 7 points (part a), there are no patterns #1-5 detected; hence, the process is in control.
b) See the chart provided above. The process is out of control since pattern 5 is detected; hence, the
process is out of control, and we should be concerned about the delivery process.
Sample
8
9
6
6
3
4
Delivery time (in days)
3
3
5
3
1
4
3
5
4
5
2
4
p = % defects
2/8 = 0.250
7/8 = 0.875
c) Delivery time is important for judging delivery quality and is available; sample size of 8 is not
sufficient for p-chart (min. of 50-100 required); x-bar-chart and R-chart would be better than pchart
2. C-chart: center line = 24, UCL = 24 + 3(24)½ = 38.7, LCL = 24 – 3(24)½ = 9.3 (chart omitted)
Zone width = (38.7 – 24)/3 or (24 – 9.3)/3 = 4.9
Zone boundaries:
38.7 = UCL
33.8 = center + 2(4.9) or UCL – 4.9
28.9 = center + 4.9 or UCL – 2(4.9)
24 = center line
19.1 = center – 4.9 or LCL + 2(4.9)
14.2 = center – 2(4.9) or LCL + 4.9
9.3 = LCL
Sample Above/
Below
1
A
2
B
3
A
4
A
5
B
6
B
7
B
8
B
9
A
10
A
Up/
Down
--D
U
D
D
U
D
D
U
U
Zone
C
B
A
C
B
C
C
B
B
A
Sample Above/
Below
11
A
12
A
13
A
14
A
15
A
16
B
17
B
18
B
19
B
20
A
Up/
Down
D
U
U
U
D
D
D
U
U
U
Zone
C
B
B
A
C
B
A
B
B
C
Sample Above/ Up/
Below Down
21
A
U
22
B
D
23
B
U
24
A
U
25
A
U
26
A
U
27
B
D
28
B
D
29
B
U
30
B
U
Pattern 5 is detected (samples 8 through 12) ⇒ process is out of control.
Zone
B
A
B
C
C
B
C
A
B
C
3. The process seems to be getting out of control (more points below the centre line than above), but at
the moment, it is still in control according to the pattern tests. However, more points below the centre
line mean that the number of complaints is fewer than the historical average (it’s a good thing). Make
sure that there is no mistake in the collection of data and construction of the control chart. If everything
is okay, then update the center line, UCL and LCL to reflect the fundamental change in the process.
12
B1. Multiple Choice Questions from Old Exams
Question
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Answer
d
c
b
d
b
c
b
d
c
a
b
d
a
b
d
a
c
d
a
b
b
d
a
a
c
C1. Textbook Discussion Questions
Process, #7
Process, #10
Process Case
JIT, #1
JIT, #3
JIT, #4
JIT, #5
JIT, #7
JIT, #10
Lecture notes, Process&Product Design, slide 4
E.g., computer-aided design (CAD), flexible manufacturing systems (FMS), robotics, and
computer-integrated manufacturing (CIM)
Biddy’s Bakery #3 – Biddy’s Bakery currently has an intermittent operation in place. To
meet the students’ proposal, Biddy’s Bakery would have to start using a continuous
operation. Continuous operations use a capital intensive process with a line flow, while
intermittent operations use a labor intensive process with a variety of flows.
Elimination of waste
Lecture notes, JIT Systems, slide 5
Toyota, Dell Computer
TQM is critical in JIT since poor quality would cause us to not deliver the right products at
the right time in the right quantities
Respect for people is important in JIT because everyone must be involved in managing and
improving production
Fast food restaurants
13
JIT Case
JIT Case
TQM, #1
TQM, #2
TQM, #3
TQM, #6
TQM, #7
TQM, #8
TQM, #10
TQM, #11
TQM, #12
TQM Case
SPC, #4
SPC, #5
SPC, #6
SPC, #7
SPC, #8
SPC, #9
Dixon #1 – A supplier such as D&S can obtain several benefits from establishing a JIT
relationship with a buyer such as Dixon. Usually, such relationships are longer term, more
cooperative, and with a small set of vendors. D&S will then have a more certain, steady
demand for their product. They should also have more accurate forecasts further into the
future. Besides these demand benefits, D&S could improve its production and distribution
efficiency. Better knowledge of the size and timing of orders would allow them to plan
operations more efficiently. As they are responsible for much of the ordering, they can
better coordinate their operations with the order cycles. However, D&S does have some
reasons to be concerned also.. The relationship shifts supply responsibility to D&S. The
guaranteed business would be at risk if D&S were to forecast or perform poorly. Further,
the responsibility for placing orders in now a D&S paid employee.
Dixon #2 – A buyer, such as Dixon, can obtain many relationships from a JIT relationship
with a supplier. Order timing becomes the responsibility of the vendor. Quality should
improve and deliveries should become more reliable. Through better coordination, the
supplier’s costs should improve, which may eventually be reflected in their price. Buyers
often have several concerns of such an arrangement. For one, seldom does a supplier have
only one customer in a market. Buyers worry that sensitive information, such as upcoming
product promotions, may become known to their competitors through the information they
share with the supplier. Buyers are also often reluctant to give up the ability to play one
vendor against another in search for the lowest price.
E.g., the quality of a university can be defined by the quality of professors, up-to-date
facilities, variety of course offerings, administrative efficiency and accuracy, perceived
prestige, etc.
Lecture notes, TQM, slide 2
Traditional notions of quality focused on inspection of products
Lecture notes, Quality, slide 5
If we hired more inspectors without changing other aspects of quality, we would find more
defects before they reach the customer; therefore, internal failure costs will increase, while
external failure costs will decrease; appraisal costs would increase since we are now paying
for more inspectors; prevention costs would remain the same
The Plan-do-study-act cycle is a procedure for continuous improvement
Lecture notes, Quality, slide 10
Lecture notes, TQM, slide 11
Lecture notes, TQM, slide 12-14
Gold Coast Advertising (GCA) #1 – It is not frequently measuring quality based on the ability
to meet customer expectations. Success is determined by meeting or exceeding customer
expectations. It is important to frequently ask customers about how they define quality
since their definition can change over time.
Lecture notes, SPC, slide 7-11
The x-bar chart is used to detect variations in the mean of the process, while the R-chart is
used to detect changes in the variability of the process; in order for a process to be in
control, both the process average and variability must be in control
The key difference is that the sample size for the c-chart is always one; each plot represents
the number of defects on one item, such as the number of spelling errors in a report
Lecture notes, SPC, slide 26
Lecture notes, SPC, slide 4
Six sigma symbolizes extremely high quality
14
C2. Short Answer Questions from Old Exams
GUIDELINES only since there is more than one way to answer short answer questions.
1. Examples of quality definitions:
• Product based – softness, strength, colour, moisturizing lotion included
• Producer based – size of paper, weight of paper, ingredients
• Consumer based – easy to blow nose, soft on skin, no more than $1 per box
Kleenex “improved quality”: Kleenex is a well established company, and facial tissue paper is a standard
item in every household. Hence, the quality of tissue paper from the product design or manufacturing
point of view would not be useful for Kleenex. Improved quality must be defined from a consumer’s
perspective.
2. Process type = project; based on characteristics such as product type (unique, much variety, custommade), customer type (Olympics organizer, one at a time), demand type (infrequent)
3. JIT is not suitable for certain demand types (very high volume, very low volume, highly fluctuating
demand).
4. JIT → lower inventory → need to have high quality products; discuss quality at the source, preventive
approach, and continuous improvement
5. JIT implementation requires all key elements to be present and integrated, so a kanban system alone
would not achieve a JIT system and its benefits
6. Discuss TQM guiding principles and stages of quality management from a service provider’s
perspective.
7. TQM foundation, quality programs, and quality culture take time to develop
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