Exam 8: Measuring and Controlling Quality

In the production of vitamin capsules,the proportion of calcium in each capsule has a specification of 48 ± 18 parts per million (ppm).An initial random sample of 100 capsules revealed a sample average calcium content of 44.5 ppm and a sample standard deviation of 3.2 ppm.Management uses - and R-charts to monitor the calcium amount using samples each of size 4. The charts depict an in-control process.The center line of the R-chart is 6.7 and the center line of the -chart is 44.8. a sample standard deviation of $3.2 \mathrm{ppm}$ . Management uses $x$ - and $R$ -charts to monitor the calcium amount using samples each of size 4 . The charts depict an in-control process. The center line of the $R$ -chart is $6.7$ and the center line of the $\bar{x}$ -chart is $44.8$ . a. Compute $C_{p}$ for this process using estimates of the process mean and standard deviation derived from the random sample. b. Compute $C_{p}$ for this process using estimates of the process mean and standard deviation derived from the control chart parameters. c. Compute $C_{p k}$ for this process using estimates of the process mean and standard deviation derived from the random sample. c. Compute $C_{p k}$ for this process using estimates of the process mean and standard deviation derived from the control chart parameters. d. What do the differences between the values of $C_{p}$ and $C_{p k}$ tell you?

In service applications,the term _____ is generally used to describe a nonconformance.

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):

To form rational subgroups for an $\bar{x}$ -chart,the goal is to choose the samples as _____ as possible.

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.

If the variation in the process is due to common causes alone,the process is said to be:

All else being constant,if the sample size in a p-chart increases from 100 to 120,the upper and lower control limits will:

Six samples of size 10 were collected.The data are provided in the following table: The upper control limit (UCL)and lower control limit (LCL)for an s-chart are:

Explain the different stages involved in the manufacturing of individual syringes at the Midwest pharmaceutical company.

A bank recently took 32 random samples of size 600 to determine the accuracy of its customer records.A customer record was considered to be nonconforming if any portion of the record was left blank.The sample data are presented below.Determine the control limits for an np-chart.

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):

Twenty samples of size 6 were collected for a variable measurement.Determine the upper control limit (UCL)and lower control limit (LCL)for an R-chart if the sum of the sample ranges equals 88.0.

Short repeated patterns in a control chart,with alternating high peaks and low valleys,are known as:

The s-chart is recommended when:

How was the problem with the third category-no purchase order on the computer system-resolved?

A measurement system may be precise but not necessarily accurate at the same time.

Define pre-control and explain under what conditions pre-control can be used.

The total observed variation in production output is the sum of the true process variation plus variation due to measurement.

How was the $\bar{x}$ -chart interpreted by the second shift operators of the syringe assembly process,after the machine had been adjusted thrice by the technician? How did the statistical consultants interpret it?

If a process is neither capable nor in control,the appropriate first step is to: