MQM 227 - Chapter 9

3. Which of the following statements about process quality control is NOT true? A. Assignable cause variation is also referred as special cause variation B. An observation outside the control limits is an example of a special cause of variation C. Common cause variation can be eliminated from the process by removing the potential causes D. The control limits will include 99.74% of the population under the normal probability distribution assuming that the process is in control

C. Common cause variation can be eliminated from the process by removing the potential causes

4. A process control chart: A. Assumes that 99.74% of special cause variation will fall between upper and lower limits B. Has upper and lower control limits set at ± 2 standard deviations from the center line C. Separates the assignable cause of variation from the common cause of variation D. Assigns causes of variation to operator, machine, or material

C. Separates the assignable cause of variation from the common cause of variation

12. One of the earliest steps in designing a quality control system is to decide on: A. The amount of inspection to use B. Who should do the inspection C. The type of measurement to be used D. Training workers to perform inspection on their own work

C. The type of measurement to be used

6. A cause-and-effect diagram: A. Identifies common causes of quality defects B. Is often used in conjunction with a Pareto chart C. Is also called a fishbone diagram D. All of the above are true

D. All of the above are true

14. Which of the following is/are assumption(s) of process control? A. Random variability cannot be eliminated unless the process is redesigned. B. Common causes represent random variability. C. Production processes are not usually found in a state of control. D. All of the above.

D. All of the above.

13. The appearance of a restaurant meal that is not satisfactory is an example of: A. Variable measurement B. Mean chart C. Range chart D. Attribute measurement E. None of the above

D. Attribute measurement

2. Sampling inspection by attributes: A. Means each item sampled is classified as defective or not defective based on quality standards B. Could be used together with process control and variable measurement as part of a quality control system C. Utilizes a discrete scale of measurement D. a, b, and c

D. a, b, and c

23. T / F - "A production process delivers large amount of scrap products. Top management has discovered that improper machine maintenance is the reason behind this failure." The above statement is an example of a special cause of variation.

T

24. T / F - Attribute control occurs when the product characteristic is measured on a continuous scale.

T

27. T / F - The seven tools of quality control are equally applicable to both manufacturing and service industries.

T

30. T / F - Six Sigma projects are typically managed by workers certified as black belts.

T

32. T / F - If failure costs were very high, a company would still use inspection.

T

33. T / F - There are two indicators of a process shift—points outside the control limits and an upward or downward trend in the process average.

T

35. T / F - Lean projects are usually simpler than six sigma projects.

T

25. T / F - The central tendency (mean) of the process is the only information needed to determine if the process is in a state of control.

F

28. T / F - In process capability analysis, the standard deviation (σ) refers to the standard deviation of sample measures.

F

29. T / F - Six Sigma efforts are aimed at eliminating waste.

F

31. T / F - Lean is another term for Six Sigma process improvement.

F

34. T / F - The quality tool that shows the relationship between two variables is a histogram.

F

1. A complete system of quality control: A. Is defined by critical control points, inspectors, measurements, costs, and other considerations B. Involves a zero defects philosophy C. Requires a continuous scale for measurement of defects D. Must include both variable and attribute measurements

A. Is defined by critical control points, inspectors, measurements, costs, and other considerations

5. A Pareto chart: A. Shows causes and effects of quality problems B. Shows the prevalence of the various types of defects that have been found C. Is not useful when first studying a quality problem D. Has both upper and lower specification limits

B. Shows the prevalence of the various types of defects that have been found

19. Which of the following statements is NOT true about six sigma quality? A. Six sigma results in 3.4 ppm defects B. Six sigma corresponds to 3 standard deviations on either side of the mean C. Six sigma can be applied to administrative and service processes as well D. Motorola invented the term "six sigma quality" in the mid-80s

B. Six sigma corresponds to 3 standard deviations on either side of the mean