O.M. Ch. 16-MC Flashcards
Quality at the source means the ultimate quality of a finished good cannot be any better than the quality of the raw material used.
False
The 1:10:100 Rule states that the value of a good increases exponentially as it progresses from supplier to manufacturer to customer.
False
If supplier documentation is done properly, incoming inspection can be completely eliminated.
True
In-process control is typically performed by the people who run the processes on the front line.
True
If no common causes affect the output of a process, we say that the process is in control.
False
Special cause variation is the result of complex interactions of variation in materials, tools, machines, information, workers, and the environment.
False
Over-adjusting a process that is in control will increase the variation in the output.
True
Keeping common cause variation from occurring is the essence of statistical quality control.
False
A discrete metric is one that is calculated from data that are counted.
True
All control charts are similar in structure, but the specific formulas used to compute control limits for them differ.
True
The sample range control chart is always analyzed before the sample mean control chart.
True
R-charts and charts are used with discrete data.
False
Whenever an unusual pattern in a control chart is identified, the process should be stopped until the problem has been identified and corrected.
True
A point below the lower control limit on a p-chart might be good news.
True
A c-chart monitors the number of conforming items.
False
A c-chart requires that the size of the sampling unit or number of opportunities for errors is constant.
True
Two key decisions in developing a sampling plan for SPC purposes are sample size and sampling frequency.
True
No hard-and-fast rules or formulas exist for computing the optimal frequency of sampling.
True
SPC is more useful for processes that operate at a high sigma level than a low sigma level.
False
A process might be off-center and still show an acceptable value of Cp.
True
Process capability is important to both product designers and process owners.
True
The three stages in manufacturing at which quality control is generally applied include all of the following except
at shipping to customers
Which of the following is not correct regarding special cause variation?
it cannot be controlled
The two basic types of metrics monitored by control charts are
discrete and continuous
Control limits for a control chart should be established when
only common-cause variation is present
Which of the following control chart occurrences is not an indication the process is out of control?
majority of points are near the center line
A p-chart monitors the
proportion of nonconforming
A c-chart monitors the
number of non-conformances per unit
When using a conventional p-chart for a process with a high sigma level, all of the following are correct except
a. the chart will provide little information for control?
For a non-centered process, which of the following must be true for the process to be declared capable?
Cpl > 1 and Cpu > 1
