MGMT 425 Exam 2 Study Guide (5,8,9,10)
Process capability calculations make little sense if the process a. data were taken over time. b. is not in statistical control. c. variations are due to common causes. d. is not initiated.
B
Short, repeated patterns in a control chart, with alternating high peaks and low valleys, are known as a. trends. b. cycles. c. shifts. d. runs.
B
Six samples of size 10 were collected. The data are provided in the following table: Sample number 1 2 3 4 5 6 Sample mean 4.80 4.62 4.81 4.55 4.92 4.65 Sample standard deviation 0.35 0.33 0.31 0.35 0.37 0.39 The upper control limit (UCL) and lower control limit (LCL) for an s-chart are a. LCL = 0.2840, UCL = 1.7160. b. LCL = 0.0994, UCL = 0.6006. c. LCL = 4.6256, UCL = 5.3256. d. LCL = 3.6750, UCL = 5.7750.
B
The output of a process is stable and normally distributed. If the process mean equals 23.5, the percentage of output expected to be less than or equal to the mean a. is less than 25 percent. b. is 50 percent. c. is greater than 75 percent. d. cannot be determined without knowing the standard deviation value.
B
A(n) _____ measurement characterizes the presence or absence of nonconformances in a unit of work. a. variable b. indicator c. attribute d. error
C
The x-chart is used for a. averages of variables data. b. individual attributes data. c. individual variables data. d. averages of attributes data.
C
True or False: Identifying potential defects and errors and stopping a process before they occur is the best approach to avoid mistakes in a process.
F
True or False: If all sample averages on an -chart fall within the control limits, all output will be conforming.
F
True or False: In determining the method of sampling, samples should be chosen to be as heterogeneous as possible so that each sample reflects the system of common causes or assignable causes that may be present at that point in time.
F
True or False: Projects generally cut across organizational boundaries but do not require the coordination of many different departments and functions.
F
True or False: Support processes generally add value directly to a product or service.
F
True or False: Support processes generally require a higher level of attention than do value-creation processes.
F
True or False: The kaizen philosophy requires a significant cultural change from all employees in the organization except top management.
F
True or False: The outputs of service processes are as well defined as manufactured products.
F
True or False: Value-creation process requirements are driven by internal customer needs.
F
True or False: The total observed variation in production output is the sum of the true process variation plus variation due to measurement.
T
True or False: A measurement system may be precise but not necessarily accurate at the same time.
T
True or False: A p-chart is used with the attribute data
T
True or False: A process is a sequence of linked activities that is intended to achieve some result, such as producing a good or service for a customer within or outside the organization.
T
True or False: Attribute measurement requires a much larger sample size than variable measurement to obtain the same amount of statistical information.
T
True or False: Control in manufacturing starts with purchasing and receiving processes.
T
True or False: Control is the activity of ensuring conformance to the requirements and taking corrective action when necessary to correct problems and maintain stable performance.
T
True or False: Control limits for variables and attributes data utilize different mathematical formulas
T
True or False: Flowcharts enable management to study and analyze processes prior to implementation.
T
True or False: If most of the points on a control chart fluctuate randomly between the control limits with no recognizable pattern, then the process is in statistical control.
T
True or False: If points on a control chart are determined to be the result of special causes, the points should be eliminated, and new control limits should be computed.
T
True or False: If the cost of investigating an operation to identify the cause of an apparent out-of-control condition is low, narrower control limits should be selected.
T
True or False: Pre-control should only be used when process capability is no greater than 88 percent of the tolerance.
T
True or False: Process capability indexes can be computed from data in an -chart.
T
True or False: Process control is the responsibility of those who directly accomplish the work.
T
True or False: Processes must be measurable and repeatable in order to apply the techniques of process management.
T
True or False: Reduction in cycle time of a process leads to improvement in quality of products as it reduces the potential for mistakes and errors.
T
True or False: The center line for the np-chart is the average number of nonconforming items per sample
T
True or False: The frequency of sampling in pre-control is often determined by dividing the time period between two successive out-of-control signals by six.
T
True or False: The impact of other processes on a particular process must be considered while designing the process, as processes rarely operate in isolation.
T
True or False: Rolled throughput yield is the proportion of conforming units that results from a series of process steps.
True
A machined part has a lower specification limit of 3.5 inches and an upper specification limit of 3.9 inches. The range for the pre-control green zone is a. 3.6 inches to 3.8 inches. b. 3.8 inches to 3.9 inches. c. less than 3.5 inches. d. 3.5 inches to 3.9 inches.
A
A precision parts manufacturer produces bolts for use in military aircraft. The specifications for bolt length are 37.50 ± 0.25 cm. The company has established an -chart and an R-chart using samples of size five. The center lines for the -chart and R-chart are set at 37.35 cm and 1.05 cm, respectively. Which of the following is the value of Cpk for this process? a. 0.07 b. 0.28 c. 0.75 d. 0.03
A
If the lower limit for a p-chart computes to a number less than zero, this indicates that a. the lower limit should be set at zero. b. the process is out of control. c. an attribute measure is incorrectly used. d. a calculation error has been made.
A
In determining whether a process is in statistical control, the _____ should be analyzed first. a. R-chart b. upper and lower control limits c. -chart d. center line
A
True or False: For variable data, the two important quality measures are the proportion nonconforming and nonconformances per unit.
F
The _____ is used to monitor the centering of the process. a. -chart b. R-chart c. p-chart d. np-chart
A
The control chart most appropriate for plotting the daily percentage of students that wait longer than 5 minutes in line at the undergraduate admissions office is a(n) a. p-chart. b. np-chart. c. x-chart. d. -chart.
A
Twenty samples of size 6 were collected for a variable measurement. Which of the following is the upper control limit (UCL) and lower control limit (LCL) for an R-chart if the sum of the sample ranges equals 88.0? a. UCL = 8.8176; LCL = 0.0000 b. UCL = 9.3016; LCL = 0.3344 c. UCL = 13.2000; LCL = 0.0000 d. UCL = 29.3921; LCL = 0.0000
A
True or False: Histograms allow you to distinguish between common and special causes of variation
F
Which of the following is NOT an indication of an out-of-control process? a. Five consecutive points fall on one side of the center line. b. Four of five consecutive points fall within the outer two-thirds region between the center line and one of the control limits. c. Two of three consecutive points fall in the outer one-third region between the center line and one of the control limits. d. A single point falls above the upper control limit.
A
Which of the following is a likely cause of the control chart pattern known as a trend? a. Aging of equipment b. Maintenance schedules c. New process operator d. Sudden power surge
A
A better alternative to using the R-chart to monitor variation is the a. np-chart. b. s-chart. c. c-chart. d. p-chart.
B
A company wishes to monitor the variation in the length of time it takes to process and send a bill to a customer. Seven bills will be randomly selected each day for a 60-day period and the length of time it takes to process and send the bill to a customer will be recorded for each bill. The appropriate control chart is a(n) a. -chart. b. R-chart. c. p-chart. d. u-chart.
B
True or False: Assembly of products in a manufacturing plant is an example of a support process.
F
A precision parts manufacturer produces bolts for use in military aircraft. The specifications for bolt length are 37.50 ± 0.25 cm. The company has established an -chart and an R-chart using samples of size five. The center lines for the -chart and R-chart are set at 35.25 cm and 1.08 cm, respectively. Which of the following is the value of Cp for this process? a. 1.333 b. 0.179 c. 0.301 d. 0.166
B
A process is said to be out of control when a. common causes are present. b. special causes are present. c. the process is not capable of meeting specifications. d. the upper and lower control limits cannot be computed.
B
After the featured distributor of electronic automation and power transmission products consolidated the types of packing slip errors into five categories, a _____ was performed. a. price evaluation b. Pareto analysis c. qualification standard d. quantification
B
All else being constant, if the sample size in a p-chart increases from 100 to 120, the upper and lower control limits will a. move farther apart. b. move closer together. c. not be affected. d. both shift upward.
B
Assuming 25 samples of size 100 were collected and a total of 96 nonconforming items were found, the upper control limit for the p-chart would be a. 0.083. b. 0.096. c. 0.137. d. 0.254
B
Defects per million opportunities (dpmo) = a. (Number of defects discovered)/Opportunities for error × 100,000. b. (Number of defects discovered)/Opportunities for error × 1,000,000. c. (Opportunities for error × Number of defects discovered)/1,000,000. d. (Opportunities for error/Number of defects discovered) × 10,000,000.
B
For variables data, the sample means are assumed to be a. exponentially distributed. b. normally distributed. c. Poisson distributed. d. binomially distributed.
B
In pre-control, which of the following zones covers the nominal specifications of a process? a. Gray zone b. Green zone c. Red zone d. Yellow zone
B
True or False: Common and special causes of variation must be eliminated before process capability can be determined.
F
The s-chart is recommended when a. the control chart calculations need to be performed by hand. b. tight control of variability in the process is required. c. the -chart is not associated with an R-chart. d. the sample size for each sample needs to be reduced.
B
To form rational subgroups for an -chart, the goal is to choose samples that are as _____ as possible. a. heterogeneous b. homogeneous c. large d. systematic
B
Which of the following charts is used to monitor the average number of nonconformances per unit when sample sizes vary? a. -chart b. u-chart c. p-chart d. c-chart
B
Which of the following is NOT one of the basic applications of a control chart? a. To establish a state of statistical control. b. To calculate the average range. c. To monitor a process to identify special causes of variation. d. To determine process capability.
B
Which of the following statements regarding an x-chart is true? a. Individual data require averaging before being plotted on it. b. It is less sensitive to many conditions that can be detected by the -chart and R-chart. c. Specification limits cannot be drawn on the chart for direct comparison with the control limits. d. The assumption of normality of observations is less critical than for the -chart and R-chart.
B
_____ is measured as the amount of error in a measurement in proportion to the total size of the measurement. a. Precision b. Accuracy c. Systematic bias d. Capability
B
61. The sample size for an x-chart a. should be between 25 and 30. b. is larger than that for an -chart. c. is equal to one. d. should be greater than one.
C
A c-chart is based on the _____ probability distribution. a. normal b. binomial c. Poisson d. exponential
C
A delivery company defines a defect as a package delivered later than the promised delivery time. Management wants to monitor the proportion of such defect packages per week and plans to sample 120 packages every week. The appropriate control chart is a(n) a. -chart. b. R-chart. c. p-chart. d. np-chart.
C
A preliminary analysis involving data entry at the featured distributor of electrical automation and power transmission products revealed that packing slips contained errors; to remedy this problem, a _____ was constructed for each day to track the number of defects found. a. Quality Assurance Committee b. sampling strategy c. u-chart d. new production process
C
Because of high test costs, a sample of single wastewater sludge is tested daily for dissolved oxygen content. The appropriate control chart(s) would be a. -chart and R-chart. b. u-chart. c. x-chart and moving range chart. d. x-chart and R-chart.
C
Collecting _____ data is usually easier than collecting _____ data because the assessment can usually be done more quickly by a simple inspection or count. a. variable; attribute b. conformances; nonconformances c. attribute; variable d. simple; complex
C
Compared to variable measurement, attributes measurement requires _____ to obtain the same amount of statistical information about the quality of the product. a. a more distributed population b. more nonconformances c. a much larger sample size d. a smaller sample size
C
Control limits are often confused with a. pre-control lines. b. center lines. c. specification limits. d. three sigma limits.
C
If a process is neither capable nor in control, the appropriate first step is to a. remove common causes of variation. b. redesign the equipment. c. remove special causes of variation. d. determine the process capability index.
C
If the process mean and variance do not change over time, the process is a. in statistical control. b. normally distributed. c. stable. d. capable.
C
If the variation in the process is due to common causes alone, the process is said to be a. out of control. b. in pre-control. c. in statistical control. d. out of capability.
C
In service applications, the term _____ is generally used to describe a nonconformance. a. cycle b. unit c. error d. trend
C
Statistical process control relies on a. process capability studies. b. dashboards. c. control charts. d. metrology.
C
True or False: Control limits for the s-chart are given by: LCLs = B3s and UCLs = B4s, where B3 and B4 are constants.
F
Variable data are a. discrete. b. not measurable. c. continuous. d. nonrandom.
C
Which of the following statements regarding a major advantage of np-charts is true? a. They can be used for variable sample sizes. b. They are more accurate than p-charts. c. They are easier to understand for production personnel than p-charts. d. The control limits are based on binomial distribution.
C
_____ is a study of variation in a measurement system using statistical analysis. a. A metrology study b. An SPC study c. A repeatability and reproducibility (R&R) study d. A calibration study
C
True or False: For a manufacturing company, legal services will be considered an example of a value-creation process.
F
A _____ is the result of some cause that gradually affects the measurement and causes the points on a control chart to gradually move up or down from the center line. a. defect b. process shift c. cycle d. trend
D
A canning company defines a "nonconformance" as an orange juice can whose diameter is beyond the upper specification limit. A manager at the canning company wants to monitor the number of such orange juice cans produced per day. Each day, an employee will randomly select 120 cans over a period of four weeks. The employee then determines and plots the number of nonconformance cans in each sample. The appropriate control chart is a(n) a. u-chart. b. R-chart. c. p-chart. d. np-chart.
D
A(n) _____ monitors the fraction of nonconforming units. a. c-chart b. u-chart c. np-chart d. p-chart
D
Each day, a manufacturing company producing circuit boards will randomly sample 60 circuit boards for a period of 25 days and then determine and plot the number of defects contained in each of these boards. The appropriate control chart is a(n) a. u-chart. b. p-chart. c. np-chart. d. c-chart.
D
For statistical process control, a good sampling method should always a. use samples of random measurements over a long period of time. b. minimize sampling cost. c. maximize sample size. d. use rational subgroups.
D
In an attempt to solve the problem of tacked syringes at a Midwest pharmaceutical product manufacturer, statistical consultants recommended _____ for the purpose of improving the tacking operation. a. ANOVA b. pre-control c. measurement system evaluation d. statistical process control (SPC)
D
Which of the following pairs of charts are used together? a. -chart and p-chart b. R-chart and p-chart c. R-chart and s-chart d. -chart and R-chart
D
True or False: A "hugging the center line" pattern in a control chart can be the result of taking each sample from a different process but not mixed together.
F
True or False: A better alternative to the -chart to monitor variation is to compute and plot the standard deviation s of each sample.
F
True or False: A c-chart is based on the binomial distribution
F
True or False: A histogram of data that resembles the normal distribution indicates that the process is in control.
F
True or False: A kaizen blitz is an improvement initiative that is gradual and continuous and is performed on a part-time basis.
F
True or False: A nonconforming unit of work is one that has no defects or errors
F
True or False: Agility might demand special strategies such as modular designs, sharing components, sharing manufacturing lines, and specialized training for employees.
F
True or False: The improvement aspect of process management focuses on continually seeking to achieve higher levels of performance, such as reduced variation, higher yields, fewer defects and errors, and smaller cycle times.
T
True or False: The larger the sample size, the narrower the control limits.
T
True or False: When constructing a u-chart, the standard deviation of each sample varies because the size of the sampling unit varies.
T
