Session 4 - Quality, Quality Tools 1 Flashcards
1
Q
Why does quality matter?
A
1- Consumers’ Safety Impact
2- Financial Impact
3- Reputation Impact
4- Legal Impact
2
Q
What types of attributes are categorized as “Other Features” that are nice to have?
A
1- Convenience
2- Reliability
3- Aesthetics
4- Customization
5- Quietness
3
Q
Who, can determine quality?
A
Only customers
4
Q
What are the two different types of Quality?
A
1- Conformance
2- Performance
5
Q
What is “Conformance” quality?
A
A product or service that “delivers on its specification”
- The degree to which a product or service “meets or exceeds customers’ needs and expectations”
- No defects
6
Q
Where does “Conformance” achieve quality?
A
Achieved quality in the “Manufacturing” or “Delivering” process
7
Q
What is “Performance” quality?
A
A product or service that competes on a “high level of performance” dimensions
- “Quality” as an operations objective
8
Q
Where does “Performance” achieve quality?
A
Achieved quality in the design process
9
Q
What are the four phases when measuring product quality?
A
Phase 1 - Design
Phase 2 - Production
Phase 3 - Use
Phase 4 - Customer Service
10
Q
What is “Quality of Design” in measuring product quality?
A
Phase 1
- Defines the “performance quality” and translates customer needs into design
11
Q
What is “Quality of Conformance” in measuring product quality?
A
Phase 2
- Produce products that “meet pre-defined specifications”
12
Q
What is “Three Abilities” in measuring product quality?
A
Phase 3
- Availability, Reliability, and Maintainability
13
Q
What is “Field Service” in measuring product quality?
A
Phase 4
- Maintenance, Repair, or Replacement
14
Q
What is one thing manufacturing can or can’t do in quality of design - Phase 1?
A
Manufacturing can’t correct design problems
15
Q
What is the purpose of Phase 2 - Quality Conformance?
A
Producing products that “meet pre-defined specifications”
- even cheap products can have high conformance quality
16
Q
When is conformance quality achieved?
A
Achieved if products match their design
17
Q
What are some tools of Quality of Conformance?
A
1- Internal Procedures
2- Better Equipment Designs
3- Statistical Process Control Tools
4- External Requirements`
18
Q
What are the three abilities in Phase 3 for measuring quality?
A
1- Reliability
2- Maintainability
3- Availability
19
Q
What is “Reliability” in Phase 3?
A
It is the mean time before failure (aka Uptime)
20
Q
What is “Maintainability” in Phase 3?
A
Mean time to repair (downtime)
- Restoration of product or service after failure
21
Q
What is “Availability” in Phase 3?
A
The proportion of time available
22
Q
How do you calculate “Availability” in Phase 3?
A
Availability = Uptime / (Uptime + Downtime)
23
Q
What is Phase 4?
A
Field Service or After-market support
- Warranty and repair/replacement of the product after it has been sold
24
Q
What are the Dimensions in Phase 4?
A
Three Dimensions
1- Promptness
2- Competence
3- Integrity
25
What is the most popular measure when it comes to measuring service quality?
SERVQUAL (service quality)
26
What are the five attributes under SERVQUAL and what do they mean?
1- Tangibles
- Physical facilities, equipment, equipment and appearance
2- Reliability
- ability to perform the promised service
3- Responsiveness
- Willingness to help customers and provide prompt services
4- Assurance
- Knowledge, courtesy of employees
5- Empathy
- Caring, individualized attention
27
What was the first stage and year in the Evolution of Quality Management?
No Quality Management
e- 1900's
28
What was the second phase and year n the Evolution of Quality Management?
Product Inspection
e- 1900's
29
What was the third phase and year in the Evolution of Quality Management?
Statistical Quality Control
Shewhart - 1940's
30
What was the fourth phase and year in the Evolution of Quality Management?
Toyota Production System
Deming, Juran, Ishikawa - 1970's
31
What was the last phase and year in the Evolution of Quality Management?
Six Sigma
GE - 1990's
32
What happened in the Product Inspection phase of the Evolution of Quality Management?
It's where companies were "reactive to internal failure"
33
What happened in the third phase of the Evolution of Quality Management?
It began "Proactive Investment in Prevention and Control"
34
What happened in the fourth phase of the Evolution of Quality Management?
Proactive investment in prevention and control
Also where "Quality Crisis" began
35
What happened in the last phase of the Evolution of Quality Management?
New Challenges:
1- Increasing customer's expectation
2- Market Competitions
36
In the trade-offs phase of managing quality, what are the four types of "Cost-of-Quality"?
1- Prevention Cost
2- Appraisal Cost
3- Internal Failure Cost
4- External Failure Cost
37
What are two categories in the "Cost-of-Quality"?
1- Cost of Quality Control
2- Cost of Quality Failure
38
Which types fall under the "Cost of quality Control" and what do they mean?
1- Prevention Cost
- cost incurred to prevent poor quality
2- Appraisal Cost
- Cost incurred while uncovering defects
39
Which types fall under the "Cost of Quality Failure" and what do they mean?
1- Internal Failure Cost
- Cost incurred with discovering poor quality before it reaches customer
2- External Failure Cost
- Cost associated with poor quality product after it reaches the customer
40
What are some examples for the four types of "Cost-of-Quality"?
1- Prevention
- Planning, Training, and Design
2- Appraisal
- Inspections, Tests, Audits
3- Internal Failure
- Rework, Scrap, Downtime
4- External Failure
- Repair Costs, Lost brand loyalty, Product recall costs
41
What is a good measure when observing the Quality vs. Cost graph?
"Optimal" level of quality with respect to minimal total cost
42
What does Good Quality Management Programs figure out?
Figure out how to achieve better quality with affordable cost and then transfer this knowledge through the company
43
What do Production Managers do?
Meet volume targets, ship on time, fulfill orders
44
What do Quality Managers do?
Ensure products quality
45
What is Quality Driving?
1- Tolerance for occasional speed increases
2- Strive for perfection (zero defects)
46
How do you achieve Quality?
using "The Quality Cycle"
1- Customer - define quality needs
2- Marketing - interpret customer needs, work with customers to design products
3- Engineering - Define design concept, prepares specifications, and defines quality characteristics
4- Never-ending process of gathering current customers needs
47
What is "Operations" and "Quality Control"
1- Operations
- Product products or services
2- Quality Control
- Plan and monitor quality
48
What is the the "Poka-Yoke" Design?
- Developed at Toyota in the 1960's
- Means mistake proofing (or fool proofing)
- Design the product and process so that mistakes can be prevented or are immediately detectable
49
What are some examples of the "Poka-Yoke" design?
A snow blower that requires two levers to be held during operation to prevent misplacing of hands in dangerous areas
Overflow outlets in the sink
Car beeping if the doors are open while the engine is running
50
What is used in Internal Quality Control?
SOP - Standard Operating Procedures
51
What is used for External Quality Requirements?
ISO 9000
(International Organization for Standardization)
52
What does ISO and ISO 9000 do?
ISO - provides a set of internationally accepted standards
ISO 9000 - certifies firms' quality management system (QMS) to ensure that firms meet customer needs within statutory and regulatory requirements related to a product or service
53
What does the FDA do?
Food and Drug Administration
- regulates drug and medical device safety and effectiveness
54
What do FDA assessors and inspectors do?
Determine whether a firm has the necessary facilities, equipment, and ability to manufacture the drug or medical device it intends to market
55
What is the general rule of process variations?
All processes have some variations
56
Can variations be Atypical?
Yes
57
What are the two causes of variations?
1- Common (random) cause
2- Assignable (special) cause
58
What is Common cause in variations?
- Causes of variations that are based on random reasons that we cannot identify
- The variation is reasonable and acceptable variation, which is within 3 standard deviations from the mean
59
What is Assignable cause in variations?
- Causes of variations that can be identified and corrected
- The variation could be due to machine, worker, materials, etc.
60
What is SPC?
Statistical Process Control
- the use of statistics to control and monitor the process quality
- to detect whether a process is "in control" or "out of control"
61
What does "in control" mean in SPC?
"in control" means that the process stays within the pre-defined process specifications
62
How is SPC implemented?
Is implemented by Sampling
- representative (multiple) samples
63
What is a fact of SPC?
Process variability is inevitable
64
What is the symbol for standard deviation?
Sigma - σ
65
What chart is used to track variations over time?
Control Chart
66
What limits are there in a Control Chart?
UCL - upper control limit
LCL - lower control limit
Mean - center line
67
What chart is used to capture the "shift of process mean"?
The x-bar chart
(Mean Control Chart)
68
What are the limits in the x-bar chart?
Same as control
UCL, LCL, and Center
69
What is the rule when it comes to variations in the mean control chart?
the X-bar chart
- the process is in control if it's within three standard deviations of the center line and within the UCL and LCL
70
What does (n) stand for?
(x̄ chart)
Sample size
- the number of measurements in each sample - NOT the number of samples
71
What does (N) stand for?
(x̄ chart)
How many samples there are
72
What is A2?
(x̄ chart)
A2 is a constant number that can be found by using the sample size
- when the sample size increases, the A2 constant decreases
73
How do you calculate the sample mean?
(x̄ chart)
the x-bar
by adding all the items in the sample size and dividing it by the sample size
74
How do you calculate the sample range?
(x̄ chart)
the R
by subtracting the largest and smallest number in the sample size
75
How do you find the x̄̄? (double x-bar)
(x̄ chart)
By adding all the sample means within the samples and dividing it by the number of samples
76
How do you find the R̄ (r-bar)?
(x̄ chart)
by adding all the sample ranges within the sample and dividing it by the numbers of samples
77
What is one of the ways to calculate the UCL and LCL in an x-bar chart?
by finding the center line (x̄̄) and adding (UCL) or subtracting (LCL) by the constant (A2) and multiplying it by the total sample range (R̄)
78
What is another name for the x̄̄ (double x-bar)?
The center line
79
What is the Range Control chart and what does it do?
The R chart
- used for Capturing the Shift in Process Variability
80
What are the main components of the R Chart?
1- Mean Range
2- Upper Control Limit (UCL)
3- Lower Control Limit (LCL)
81
What happens to the A2, D3, and D4 constant when the sample size increases?
A2 - decreases
D3 - Increases
D4 - Decreases
82
What does the (n) and (N) mean for the R chart?
(n) = number of measurements in each sample (not the number of samples) - sample size
(N) = number of samples
83
How do you calculate the R̄ (r-bar)?
(r-chart)
Adding all the sample ranges in the sample and dividing it by the number of samples
84
What is another use for the R̄ (r-bar)?
(r-chart)
It can be used as the center line between the LCL and UCL
85
How do you calculate the UCL and LCL in an R Chart?
UCL = multiplying the D4 constant and the R̄ (r-bar)
LCL = multiplying the D3 constant and the R̄ (r-bar)
86
What happens when there is a change in the process variability within an original and new sample?
The process mean stays the same but the process becomes more variable
87
What is a summary for the x̄ (x-bar) chart and what is it used for?
You plot the sample means
- are used to check if the process mean has changed
88
What is a summary for the R chart and what is it used for?
You plot the sample ranges
- are used to check if the process variability has changed
89
What is the two step approach?
Step 1 - control limits should always be calculated based on samples collected from a process that is known to be under control
Step 2 - these control limits will then be used to test future (new) samples to see if the process still remains under control
90
What are the two types of measurement in a P Chart?
Variable Measurement
Attribute Measurement
91
What is "Variable Measurements"
Outputs can be represented by a continuous number
ex. Height, Width, Concentration, Processing Time
92
What methods can be used for "Variable Measurements"
x̄ (x-bar) chart
R chart
93
What is "Attribute Measurements"
Output is represented by a discrete response
ex. Good / Bad , Pass / Fail , On-time / Delay
94
What methods can be used for "Attribute Measurements"
P Chart
95
How many steps are there in constructing a P chart?
There are five steps
96
What is Step 1 in the P chart construction?
For each sample, count the number of defective outputs
(count the number of outputs that failed the attribute test - denote defective outputs as Xi )
97
What is Step 2 in the P chart construction?
For each sample, calculate the proportion of defective outputs
[ number of defective outputs divided by the sample size (n) ]
Pi = Xi / n
98
What is Step 3 in the P chart construction?
Estimate for the average proportion of defects based on the results of N samples
(also known as the "Mean")
p̄ (P bar) equals the average proportion of defects
N is the number of samples you have
p̄ = sum of all proportions (p) in the sample divided by the number of samples
99
What is Step 4 in the P Chart construction?
Estimate the standard deviation of the average proportion of defects
σp (sigma p) = √ [ p̄ (1-p̄ ) ] / n
square root of the p bar multiplied by 1 minus the p bar divided by the sample size
100
What is the final step in the P chart construction?
Set the control limits
(finding the UCL and LCL)
UCL = mean + 3(σ)
LCL = mean - 3(σ)
101
What is the rule is the LCL is lower than 0?
( LCL < 0 )
If LCL is lower than zero, then the LCL will be set equal to zero
