QOM 2017 - Six Sigma - Test 2013B1

Question 1

In the context of x-bar chart, which of the following condition is not assumed?

a. The distribution of the x-bar follows normal distribution 

b. The distribution of the individual x follows normal distribution 

c. The variance of the x-bar is never greater than the variance of the individual x 

d. The average of the x-bar serves as an estimate of the process mean

Answer 1

b. The distribution of the individual x follows normal distribution

Question 2

1. The process capability index Cpk
   a. does not help analyzing variation 

   b. is always preferable to Cpl and Cpu 

   c. is good to be used when we suppose that the process is 
not centered on target 

   d. does not give an indication of dispersion and closeness to target

Answer 2

c. is good to be used when we suppose that the process is

not centered on target

Question 3

If the process is in statistical control, it implies that

a. The process has natural and unnatural variation

b. There is a statistically systematic variation in the process

c. There is no points falling outside the limits of the control chart
d. There is only random variation in the process

Answer 3

d. There is only random variation in the process

Question 4

When testing the intercept and slope of a regression line, it is found out that the p-values are much lower than 5%, it can be concluded that

a. The X-variable causes the Y-variable

b. The coefficient of determination is greater than 95% 

c. The Y-variable is independent of the X-variable 

d. None of the above

Answer 4

d. None of the above

Question 5

1. With respect to linear regression analysis, which of the following is statement is false?
   a. Linear regression analysis is sensitive to outlier 

   b. For the regression model to be valid, the residuals should be 
independently, identically, and normally distributed 

   c. One can use the regression model to predict both within and without the range of data in the X-variable 

   d. One can use the regression model to predict only within the range of data in the X-variable

Answer 5

c. One can use the regression model to predict both within and without the range of data in the X-variable

Question 6

1. When the subgroup size of an x-bar chart is increased
   a. Both the lower and the upper control limits will decrease 

   b. Both the lower and the upper control limits will increase 

   c. The upper control limit will increase, but the lower control limit 
will decrease 

   d. The upper control limit will decrease, but the lower control limit will increase

Answer 6

d. The upper control limit will decrease, but the lower control limit will increase

Question 7

If three-sigma control limits are used with one point data collected every day for the x-bar chart

a. There will be, on average, one false alarm every month

b. There will be, on average, one false alarm every six months

c. There will be, on average, one false alarm every year 

d. There will be, on average, one false alarm every two years

Answer 7

c. There will be, on average, one false alarm every year

Question 8

If four-sigma control limits are used instead of three-sigma, what will happen to the average run length when the process is stable (ARL0) and when the process is unstable (ARL1)

a. Both ARL0 and ARL1 will increase

b. ARL0 will increase, but ARL1 will decrease
c. ARL0 will decrease, but ARL1 will increase
d. Both ARL0 and ARL1 will decrease

Answer 8

a. Both ARL0 and ARL1 will increase

Question 9

When there is one point falls outside either the lower or the upper limit of a control chart, it implies that

a. The process is stable

b. There is an assignable cause 

c. The process is not capable 

d. None of the above

Answer 9

d. None of the above

Question 10

7. The purpose using potential-FMEA in a Six Sigma project is:
   a. To create a list of underlying factor that might influence the 
variation in y 

   b. To visualize the status of the control of the most 
influential factors in the underlying system for y 

   c. To sort out the most relevant factors influencing variation in y 

   d. To create a basic document as input for audit

Answer 10

b. To visualize the status of the control of the most

influential factors in the underlying system for y

Question 11

The control plan is one of major deliveries from a Six Sigma project. It contains everything below EXECPT:

a. Calculations and relation of R2 and R2adj

b. Links between critical factors and big Y 

c. SOP for preventive maintenance and gauge control
d. Local control of process correction and resources

Answer 11

a. Calculations and relation of R2 and R2adj

Question 12

In the Analysis of variance (ANOVA), the scope is to:

a. check the model assumptions
b. compare more than two treatments
c. verify that the error is normally distributed
d. show that a factor is significant

Answer 12

b. compare more than two treatments

Question 13

13. The main difference between a control chart for variable and one for attribute is:
    a. We use the control chart for attributes when the process in control 

    b. We use the control chart for variables in combination with control limits 

    c. We use a control chart for attributes when we cannot have quantitative measurements from the process 

    d. None of the above 


Answer 13

c. We use a control chart for attributes when we cannot have quantitative measurements from the process

Question 14

DPMO stands for:

a. Define the Project, Measure and Observe b. Dot Plot Multi Objective

c. Defects Per Million Opportunities

d. Defects, Problems, Measures, Optimization

Answer 14

c. Defects Per Million Opportunities

Question 15

The DMAIC is:

a. Antithetic to the PDCA cycle

b. A framework for developing a six sigma project
c. A tool for obtaining six sigma quality

d. A tollgate

Answer 15

b. A framework for developing a six sigma project

Question 16

Variation Mode and Effect Analysis is:
a. The equivalent of FMEA for large scale problems
b. A structured way to analyze variation of a key product
characteristic
c. A structured way to hide noise factors
d. None of the above

Answer 16

b. A structured way to analyze variation of a key product

characteristic

Question 17

A statistical problem is:
a. A linear model with an error term
b. The conversion of a real problem into data and
methodology
c. The outcome of a six sigma project
d. The starting point of a six sigma project

Answer 17

b. The conversion of a real problem into data and

methodology

Question 18

The small ys and the CTQs in a Effective Scoping analysis:
a. Can be respectively considered as the input and the output of a
process
b. Are always strongly correlated
c. The former are related to customer wants, the latter are
related to product features
d. Provide the direction for product improvement

Answer 18

c. The former are related to customer wants, the latter are

related to product features

Question 19

A robust design is characterized by:

a. Insensitiveness to noise factors
b. Absence of noise factors
c. Use of Design of Experiments
d. Low variation in performances

Answer 19

a. Insensitiveness to noise factors

Question 20

Outliers:
a. are special causes of variation
b. need to be eliminated from a dataset
c. are highlighted only through probability plots
d. are opportunities for better understanding and
improvement

Answer 20

d. are opportunities for better understanding and

improvement

Question 21

Following the principles of sequential-DOE. What would you recommend for the next step of experimentation in this situation?

a. Full-factorial experiment
b. Folding
c. Replication
d. Center points

Answer 21

a. Full-factorial experiment

Question 22

Which of the following statement is true in the case when the control limits of x-bar chart of subgroup size four, coincide with the specification limit, that is, UCL=USL and LCL=LSL?
A. Cp=Cpk=1
B. Cp1
D. None of the above

Answer 22

D. None of the above