Question 6
First we should define the benchmark that we are going to compare with. Though
different programs have different courses and requirements we can still find benchmarks
from other programs. So we define the overall quality of the courses (includi
1
C AND U CHARTS FOR
NUMBER OF DEFECTS
C Chart for Number of Defects
2
Examples:
contaminants per sample of recycled plastic
defects (all types) per sample of cars
defects (scratches, bubbles, etc.) per sample of
a painted surface
You choose sample size
0
Name:_
540:433 Quality Engineering and Statistics Midterm I
1.
2016 SOLUTION
(10 points) Give the reduced model that relates the outcome Y to the factors including error
term.
Performance Measure, for 2 replicates
Factor B: -1 Factor B: +1
Factor A: -1
2
1
STATISTICAL PROCESS
CONTROL INTRODUCTION
There is variation in ALL processes!
2
Two types
Chance Causes - many unavoidable
relatively small causes of variation
Assignable Causes- unusual things that
happen that cause variation
Names for Assignable and C
Name_
540:433 Quality Engineering - Examination II - Fall 2016 SOLUTIONS
1. (10 points) To monitor the dimension of a part, the following
X
and R charts with a sample
size of 4 are in use. (NOT NECESSARILY STANDARD CONTROL CHARTS)
X
Chart has UCL=52.5CL=5
1
AN EXPERIMENT
REVEALS A MODEL
When are factorial experiments
appropriate?
2
2 levels means linear model
MRE
beef
yield
MRE
beef
yield
20 mins
25 mins
30 mins
20 mins
25 mins
30 mins
Linear models often work though
most physical models are non-linear
3
I
Name:_
Confidence Intervals, Significant Differences and the p value
1. From historical data the mean of the amount filled is 40 and the standard deviation is 1.5.
Sketch the distribution of the amount filled & sketch the distribution of the sample averag
540:311DETERMINISTICMODELSIN
OPERATIONSRESEARCH
Lecture13:Chapter6.56.10
ClassMeeCng:ThuApril14th10:2011:40am
Prof.W.ArtChaovalitwongse
6.5FindingtheDualofanLP
Associated with any LP is another LP called the dual.
Knowledge of the dual provides interestin
1
SIGNIFICANCE WITH
REPLICATES
Which effects are significant in 2k
Factorial Experiment with 2 reps
2
Model
Assumption:
same sd for
all
treatments
Which effects (and coefficients) stat
significantly different than 0?
Answer rests on estimate of
How to est
1
ATTRIBUTE CONTROL
CHARTS
Attribute Control Charts for sample
statistics based on discrete r.v.
2
Count Defectives Binomial 0,1,2,n
Count Defects Poisson 0,1,2,
lower case
n is
sample
size
i>clicker
3
Which of the following should be monitored
by a P Cha
Question 2
1. Overall sigma level:
DPMO=(6/5000)*1000000/5=240
So its approximately 5 sigma with off-centering of 1.5 sigma
2. For the characteristic that showed two defects:
DPMO=(2/5000)*1000000=400
Its still about 5 sigma with off-centering of 1.5 sigm
Table 1 - Raw Data
Defect Category
Get up
before
10am
Tooth
brushing
Having
breakfast
Take
everything
Pefect
parking
Taking
exercise
Keep in
touch with
parents
Total
Day #1
Day #2
Day #3
Day #4
Day #5
Day #6
Day #7
Day #8
Day #9
Day #10
Day #11
Day #12
Da
MADHURI
Quality Assurance
SUMMARY
Over 7+ years of experience in QA testing methodologies and automated testing tools.
Technical expertise in Automation / Test Management tools like Quick Test Pro, Win Runner, Load
Runner, Test Director and Mercury Qualit
1
ACCEPTANCE SAMPLING
Accept or reject a lot?
What is a lot?
Goal: decision making,
not parameter estimation
Also called lot sentencing
Basic Idea of Acceptance
Sampling
3
Consumer receives a large lot
Take small sample, n
Count defectives, D
Accept if
D
1
PROCESS CAPABILITY,
STRATIFICATION, MIXING
Process Capability
2
Can the process do the job the customer
wants?
Is the process a good match for the
customer?
Process capability compares consumer
specifications to process parameters
3
Consumer
specificat
1
CONTROL CHART FOR
INDIVIDUAL
MEASUREMENTS
Sometimes a sample of 5 measurements
in a row doesnt make sense
2
Oven temperature
Inventory level
Pressures
Accounts payable
If variance in sample reflects
measurement error only, use
sample size N=1
Individual
1
CONSTRUCTING X-BAR
AND R CONTROL CHARTS
i>clicker
2
1.
2.
3.
4.
Which of these sample statistics belong on
variables control charts?
Sample
Sample
Sample
Sample
average amount filled by filler
range for dimension of parts
fraction defective of glass cup
1
SIGNIFICANCE WITH
ONLY 1 REPLICATE
Finding stat sig effects in
2k Experiment with rep
2
Model
Finding significant effects rests on
estimate of
How to estimate with just 1 replicate?
Fishing Experiment: 25 Factorial
Design with 1 replicate
3
How many fac
1
SEQUENTIAL EXPERIMENTS,
RANDOMIZATION,
BLOCKING
Do a sequence of experiments
2
Screening
Start with many
possible factors and
identify important
ones with big main
effects
Modeling
Create a refined model
with focus on
main and interaction
effects
Reason