IASSC Green Belt Study Guide
If the chance that any of five telephone lines is busy at any instant is 0.01, then what is
the probability that all the lines are busy? - ANS-(0.01)^5
Who should complete the control phase after the successful completion and
implementation of the first four phases of DMAIC? - ANS-The complete team is the
most desirable option.
To increase the power of experiments, what is the best option in the hands of the Six
Sigma team? - ANS-Increase sample size
Which of the techniques used in DOE helps you in eliminating errors due to nuisance
factors? - ANS-Blocking
Hypothesis testing is usually done to: - ANS-1) Statistically validate if the sample mean
belongs to the population, 2) statistically validate if means of two groups are the same
or if they are significantly different, and 3) statistically validate if variances of two groups
are the same or if they are different.
What is the concept behind PDCA? - ANS-Continuous improvement
What are the experiments called while performing one experiment with five repetitions?
- ANS-Replications
Which type of chart is used for small shifts in variation? - ANS-CUSUM
What are the distinct types of variation that are displayed in control charts? -
ANS-Chance (common or random) and assignable (special)
Which of the following is an advantage of the production of a product in large lots? -
ANS-Machine efficiencies
A sample is to a statistic as a population value is to a: - ANS-Parameter
A calculation for reproducibility results in a value of 0 (zero), while repeatability yields a
positive number. Without any other considerations, what conclusion can be made
,regarding the reproducibility result? - ANS-A reproducibility of zero means there is no
operator effect on this measurement.
The average number of major storms in a city is 2 per year. What is the probability that
exactly 3 storms will hit next year? - ANS-0.180 or 18%
Why are scatter diagrams useful in problem-solving? - ANS-They show relationships
between variables.
The advantage of using the modern designed method of experimentation, rather than
the classical OFAT, is that: - ANS-Fewer terms and measurements are needed for valid
and useful information.
What does ANOVA stand for? - ANS-Analysis of variance
Which quality tool would not be expected to be used during the results confirmation
stage of a problem solution? - ANS-Flow chart
Use a process flow chart in the Define and Measure stage.
If 6 consecutive samples were taken from a process and precisely measured, you can
still expect differences. What type of variation would be the most difficult one to
determine? - ANS-Lot-to-lot variation
Which of the following inference tests does NOT require the knowledge of a test or
population variance? - ANS-Chi-square test
Which of the following is the LEAST likely candidate to assist in the problem definition
stage of Six Sigma? - ANS-Control charts
Control charts are used in the Measure and Control phases. Remember: The process
must first be brought into statistical control by detecting and acting upon special causes
of variation. Then its performance is predictable, and its capability to meet customer
expectations can be assessed (Cp and Cpk), which is done in the Measure phase.
What is the name of the condition if you are running a 7x4 fractional experiment, and
you know factors A, B, C, D, and E are independent of each other, but you suspect
factors F and G are not independent. You conducted a small sub-experiment and
discovered a high correlation between factors F and G. - ANS-Collinearity
, If P(A) is 0.6 and P(B) is 0.5 and the probability of either event happening is 0.85, what
is the probability of both the events occurring? - ANS-0.25 (additive rule)
A process has a high variability and an off-centered mean. What is the first action the
team needs to take? - ANS-Center the mean
What is the use of scatter diagrams? - ANS-Display correlation
Five samples are drawn out of a population of 200, with each sample being of size 5.
The sample means are 2, 2.5, 3, 2.6, and 4. What is the population mean? - ANS-2.8
In the IT sector, time and effort spent in testing the software, fixing bugs, and retesting
would be considered as what type of waste? - ANS-Defects
What is the need to plot data points on the least squares line if a probabilistic regression
model exists? - ANS-To check for fit; there may be a calculation error.
The line fitted to the paired data points must be such that the sum of the squares of the
vertical distances from the points to the line is as small as possible.
A team of Six Sigma has reached the control stage of DMAIC. The team has
successfully reduced the defect of fabric critical stains from 73 to 1 per fabric roll. Now
what type of control chart should the team recommend? - ANS-A control chart based on
the Poisson distribution such as the u-chart.
Continuous data:
I-MR Chart (individual data points, destructive testing)
Xbar and R Chart (subgroups)
Xbar and s Chart (subgroups with SD)
Discrete data (constant or varying subgroup size):
np Chart (Defectives, # of units rejected)
p Chart (Defectives, % of units rejected)
c Chart (Defects, # of defects)
u Chart (Defects, average # of defects)
What would be considered the most important element in the deployment of Six Sigma?
- ANS-Management support
If the chance that any of five telephone lines is busy at any instant is 0.01, then what is
the probability that all the lines are busy? - ANS-(0.01)^5
Who should complete the control phase after the successful completion and
implementation of the first four phases of DMAIC? - ANS-The complete team is the
most desirable option.
To increase the power of experiments, what is the best option in the hands of the Six
Sigma team? - ANS-Increase sample size
Which of the techniques used in DOE helps you in eliminating errors due to nuisance
factors? - ANS-Blocking
Hypothesis testing is usually done to: - ANS-1) Statistically validate if the sample mean
belongs to the population, 2) statistically validate if means of two groups are the same
or if they are significantly different, and 3) statistically validate if variances of two groups
are the same or if they are different.
What is the concept behind PDCA? - ANS-Continuous improvement
What are the experiments called while performing one experiment with five repetitions?
- ANS-Replications
Which type of chart is used for small shifts in variation? - ANS-CUSUM
What are the distinct types of variation that are displayed in control charts? -
ANS-Chance (common or random) and assignable (special)
Which of the following is an advantage of the production of a product in large lots? -
ANS-Machine efficiencies
A sample is to a statistic as a population value is to a: - ANS-Parameter
A calculation for reproducibility results in a value of 0 (zero), while repeatability yields a
positive number. Without any other considerations, what conclusion can be made
,regarding the reproducibility result? - ANS-A reproducibility of zero means there is no
operator effect on this measurement.
The average number of major storms in a city is 2 per year. What is the probability that
exactly 3 storms will hit next year? - ANS-0.180 or 18%
Why are scatter diagrams useful in problem-solving? - ANS-They show relationships
between variables.
The advantage of using the modern designed method of experimentation, rather than
the classical OFAT, is that: - ANS-Fewer terms and measurements are needed for valid
and useful information.
What does ANOVA stand for? - ANS-Analysis of variance
Which quality tool would not be expected to be used during the results confirmation
stage of a problem solution? - ANS-Flow chart
Use a process flow chart in the Define and Measure stage.
If 6 consecutive samples were taken from a process and precisely measured, you can
still expect differences. What type of variation would be the most difficult one to
determine? - ANS-Lot-to-lot variation
Which of the following inference tests does NOT require the knowledge of a test or
population variance? - ANS-Chi-square test
Which of the following is the LEAST likely candidate to assist in the problem definition
stage of Six Sigma? - ANS-Control charts
Control charts are used in the Measure and Control phases. Remember: The process
must first be brought into statistical control by detecting and acting upon special causes
of variation. Then its performance is predictable, and its capability to meet customer
expectations can be assessed (Cp and Cpk), which is done in the Measure phase.
What is the name of the condition if you are running a 7x4 fractional experiment, and
you know factors A, B, C, D, and E are independent of each other, but you suspect
factors F and G are not independent. You conducted a small sub-experiment and
discovered a high correlation between factors F and G. - ANS-Collinearity
, If P(A) is 0.6 and P(B) is 0.5 and the probability of either event happening is 0.85, what
is the probability of both the events occurring? - ANS-0.25 (additive rule)
A process has a high variability and an off-centered mean. What is the first action the
team needs to take? - ANS-Center the mean
What is the use of scatter diagrams? - ANS-Display correlation
Five samples are drawn out of a population of 200, with each sample being of size 5.
The sample means are 2, 2.5, 3, 2.6, and 4. What is the population mean? - ANS-2.8
In the IT sector, time and effort spent in testing the software, fixing bugs, and retesting
would be considered as what type of waste? - ANS-Defects
What is the need to plot data points on the least squares line if a probabilistic regression
model exists? - ANS-To check for fit; there may be a calculation error.
The line fitted to the paired data points must be such that the sum of the squares of the
vertical distances from the points to the line is as small as possible.
A team of Six Sigma has reached the control stage of DMAIC. The team has
successfully reduced the defect of fabric critical stains from 73 to 1 per fabric roll. Now
what type of control chart should the team recommend? - ANS-A control chart based on
the Poisson distribution such as the u-chart.
Continuous data:
I-MR Chart (individual data points, destructive testing)
Xbar and R Chart (subgroups)
Xbar and s Chart (subgroups with SD)
Discrete data (constant or varying subgroup size):
np Chart (Defectives, # of units rejected)
p Chart (Defectives, % of units rejected)
c Chart (Defects, # of defects)
u Chart (Defects, average # of defects)
What would be considered the most important element in the deployment of Six Sigma?
- ANS-Management support
