Provided by James R. Martin, Ph.D., CMA
Professor Emeritus, University of South Florida
SPC Main Page| SPC Discussion Questions
| Graduate Management Accounting Course
Note: Questions 1-17 are from MAAW's Textbook Chapter 3 Extra MC questions.
1. Using the terminology of statistical control, the variation within a stable system
a. is random
variation.
b. results from common causes.
c. is
predictable within a range.
d. a and b.
e. all of the above.
2. Using the terminology of statistical control, the variation outside the control limits on an X-bar or range chart
a. is viewed as uncontrollable.
b. is assumed to
have been caused by special or assignable causes.
c. indicates
that the system is probably out of control.
d. b and c.
e. all of the above.
3. One type of error a manager can make is to blame a worker for an undesirable variation that is caused by the system. Refer to this as a type I error. Another type of error a manager can make is to blame the system when a worker caused the undesirable variation. Refer to this as a type II error. If a company changed the basis for the upper and lower limits on a control chart from three standard deviations to two standard deviations
a. the number of type
I errors would increase.
b. the number of
type II errors would increase.
c. the number of
both types of errors would increase.
d. the number of
both types of errors would decrease.
e. there is no
basis for choosing an answer.
4. One type of error a manager can make is to blame a worker for an undesirable variation that is caused by the system. Refer to this as a type I error. Another type of error a manager can make is to blame the system when a worker caused the undesirable variation. Refer to this as a type II error. If a company changed the basis for the upper and lower limits on a control chart from two standard deviations to three standard deviations
a. the number of
type I errors would increase.
b. the number of type
II errors would increase.
c. the number of
both types of errors would increase.
d. the number of
both types of errors would decrease.
e. there is no
basis for choosing an answer.
5. Using the terminology associated with statistical process control (SPC), the variation within a stable system is
a. predictable
within a range of values.
b. controllable.
c. in control.
d. a and b.
e. a and c.
6. Using the terminology associated with SPC, the variations resulting from common causes are attributed to
a. an out of
control situation which should be investigated.
b. an in control
situation which should not be investigated.
c. an out of
control situation which should not be investigated.
d. an in control
situation which should be investigated.
e. none of the above.
7. Using the terminology of statistical process control, a variation caused by the system is
a. common cause
variation.
b. assignable cause variation.
c. special cause
variation.
d. a and b.
e. b. and c.
8. Using the terminology of statistical process control, a variation that indicates that the system may be out of control is
a. common cause variation.
b. assignable cause variation.
c. special cause
variation.
d. a and b.
e. b. and c.
9. Using the terminology of statistical process control (SPC), Type I errors are where common cause variation is treated as assignable cause variation. Type II errors are where assignable cause variation is treated as common cause variation. Which of the situations below would minimize type II errors?
a. Use SPC
charts where the limits are based on 3 standard deviations.
b. Use SPC
charts where the limits are based on 2 standard deviations.
c. Use SPC
charts where the limits are based on 1 standard deviation.
d. Use budget
comparisons against actual results without using the concept of SPC.
10. Which of the situations below would minimize type I errors?
a. Use SPC charts
where the limits are based on 3 standard deviations.
b. Use SPC
charts where the limits are based on 2 standard deviations.
c. Use SPC
charts where the limits are based on 1 standard deviation.
d. Use budget
comparisons against actual results without using the concept of SPC.
11. Using the terminology of statistical process control (SPC), a stable system is
a. efficient.
b. predictable.
c. in control.
d. b and c.
e. All of the above.
12. In general, finding and correcting an assignable cause variation
a. represents an
improvement in the system.
b. returns the system
from an unstable to a stable state.
c. represents a
type I error.
d. a and b.
e. b. and c.
13. Conceptually, control requires
a. standards.
b. a stable system.
c. statistically
established limits.
d. a. and b.
e. b. and c.
14. Statistically, an improvement in a system is defined as
a. an
improvement in the mean outcome.
b. a decrease in the system variability.
c. a correction
of an assignable cause.
d. a and b.
e. all of the above.
15. When using the SPC methodology, a system is said to be stable when
a. the system is
efficient.
b. the mean and
range of variation caused by the system are controllable.
c. the mean and range
of variation caused by the system are predictable.
d. the
performance of the system is improving.
e. none of these.
16. When using a statistical control chart (SPC), a point outside the control limits is attributed to
a. common or
random causes.
b. assignable or
special causes.
c. a problem caused by the system.
d. a and c.
e. b and c.
17. A predictable range of variation in the output of a particular worker occurs on a routine basis. This variation represents
a. common cause
variation and is uncontrollable.
b. common cause variation and is controllable.
c. assignable
cause variation and is uncontrollable.
d. assignable cause variation and is controllable.
e. none of these.
18. Joiner and Gaudard use the term structural variation in discussing Deming’s theory. This is
a. common cause variation and uncontrollable.
b. common cause variation and controllable.
c. assignable
cause variation and uncontrollable.
d. assignable cause variation and controllable.
e. none of these.
19. Deming used the red bead experiment to teach that
a. most of the
variation in a system is assignable cause variation.
b. most of the variation in a system is common cause
variation.
c. the variation
caused by the system is equally distributed across a group of workers.
d. a. and c.
e. b. and c.
20. The red bead experiment was designed to show that
a. workers tend to control their own performance.
b. special or
assignable causes account for most of the variation in performance.
c. common or random causes account for most of the variation
in performance.
d. a balanced plant is not obtainable.
e. a and c.