Exam 3: Statistical Process Control

If a sample of 40 units of output found 500 defects,then the 3-sigma upper control limit for the chart would be

When constructing a control chart for the first time,all points should be within the control limits indicating the process is in control.

If the quality of a process's output is determined by classifying the output as being defective or not defective,use a(n)___ control chart.

A company produces a product which is designed to weigh 10 oz.,with a tolerance of + 0.5 oz.The process produces products with an average weight of 9.95 oz.and a standard deviation of 0.10 oz.The process capability index for this process,with z = 3,is

A sequence of sample points that display a pattern is known as a run.

When a control chart detects no special cause variation in a process,the upper and lower control limits are the same value.

Control charts are never implemented until special cause variation has been detected in a process.

An R-chart monitors the robustness of a process.

It is possible to have low variation within samples while at the same time having high variation between sample means.

Tolerances and specification limits report similar information for a given product design.

Process control charts are rarely useful for monitoring and controlling the output of service processes.

The range is the difference between the smallest and largest values in a sample.

Statistical process control involves monitoring and controlling a process to prevent poor quality.

The process capability index is used only for p and c charts while the process capability ratio is used only for and R charts.

Which of the following control charts is used to monitor the number of defective items within a sample?

Attribute (qualitative)control charts are used to monitor descriptive characteristics of the output of a process.

Statistical process control is based on a philosophy of inspection as opposed to prevention.

Which of the following control charts is used to control the variation within samples?

One reason some companies fail in their attempt to apply statistical process control is lack of training.

Construction and use of an -chart is based on an assumption that the sample points are normally distributed around the centre line.