Exam 18: Statistical Process Control

The width of a bronze bar is intended to be one-eighth of an inch (0.125 inches).Inspection samples contain five bars each.The average range of these samples is 0.01 inches.What are the upper and lower control limits for the x-bar and R-chart for this process,using 3-sigma limits?

The higher the process capability ratio,the greater the likelihood that process will be within design specifications.

A hospital-billing auditor has been inspecting patient bills.While almost all bills contain some errors,the auditor is looking now for large errors (errors in excess of $250).Among the last 100 bills inspected,the defect rate has been 16%.Calculate the upper and lower limits for the billing process for 99.7% confidence.

________ is a method of measuring samples of lots or batches of product against predetermined standards.

The ________ is a quality control chart that indicates when changes occur in the central tendency of a production process.

The ________ is the lowest level of quality that we are willing to accept.

A run test is used

________ is variation in a production process that can be traced to specific causes.

Which of the following is true about cutting costs at Canada Bankers Life Assurance Company?

The index measures the difference between desired and actual dimensions of goods or services produced.

The x-bar chart,like the c-chart,is based on the exponential distribution.

A Type II error occurs when

A nationwide parcel delivery service keeps track of the number of late deliveries (more than 30 minutes past the time promised to clients)per day.They plan on using a control chart to plot their results.Which type of control chart(s)would you recommend?

The p-chart tells us whether there has been a

Plots of sample ranges indicate that the most recent value is below the lower control limit.What course of action would you recommend?

A retail store manager is trying to improve and control the rate at which cashiers sign customers up for store credit cards.Suppose that the manager wants the maximum standard deviation of the sampling distribution to be 5% and he cannot estimate p-bar.How many observations per sample would this require?

Pierre's Motorized Pirogues and Mudboats is setting up an acceptance sampling plan for the special air cleaners he manufactures for his boats.His specifications,and the resulting plan,are shown on the POM for Windows output below.Pierre wants acceptance sampling to remove ALL defects from his production of air cleaners.Explain carefully why this won't happen.

The x-bar chart indicates that a gain or loss of uniformity has occurred in dispersion of a production process.

What does it mean for a process to be "capable"?

Pierre's Motorized Pirogues and Mudboats is setting up an acceptance sampling plan for the special air cleaners he manufactures for his boats.His specifications,and the resulting plan,are shown on the POM for Windows output below.In relatively plain English (someone else will translate for Pierre),explain exactly what he will do when performing the acceptance sampling procedure,and what actions he might take based on the results.