FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 16: Quality Control and Spc

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 1

True/False

Review LaterAdd Note

Review Later

In manufacturing, quality control is generally applied at the receiving stage from suppliers, during various production processes, and at the finished goods stage.

Correct Answer

verified

Show Answer

Question 2

Essay

Review LaterAdd Note

Review Later

A Procter and Gamble factory process fills boxes with detergent.Construct an appropriate set of control charts to monitor the process.Historical data for fill weight (in ounces) of eight samples is presented below.A sample size of six was used. a.Compute the limits for both an R chart and x-bar chart.Compare the sample results to the limits of the charts. b.Briefly explain what the quality control charts tell you.What actions, if any, would you take?

Correct Answer

verified

a.UCL_R = (2.004)(.305) = 0.611 LCL_R = (0)(.305) = 0 n = 6 ; R-bar = 2.44/8 = 0.305 x-bar = 128.24/8 = 16.03 R chart is in control UCL_X = 16.03 + (0.483)(.305) = 16.18 LCL_X = 15.88 b.R-bar chart is stable and in control but x-bar chart is not in SPC.Stop the process and investigate sources (root causes) of error.

Question 3

True/False

Review LaterAdd Note

If the mean in the range chart shifts down significantly, it indicates that the variation in the process has decreased.

Find the control limits for a c chart with $\overline{c}$ = 7.

Quality at the source means that quality is controlled by

Which of the following is not related to a continuous metric?

Regarding special cause variability, all are true except

A process is considered to be in control when all common and special causes have been eliminated.

Over-adjusting a process that is in control will usually increase the variation in the output.

Flaws are counted on a standard steel plate (sheet).Each sheet has the exact same dimensions.Ten sheets are selected at random and the number of flaws per sheet is as follows. Determine the lower and upper control limits for a c chart..

p-charts

As long as no points are outside of the control limits in a control chart, the process would be considered to be in control

The center line (p-bar) for a p-chart is 0.50 with an UCL = 0.70 and a LCL = 0.35.The results of the next eight sample means are 0.45, 0.60, 0.39, 0.44, 0.48, 0.53, 0.54, and 0.61.What would you do?

A key element of a control system is the ability to measure performance and compare it to a performance standard.

A bottling process sometimes results in overfills or underfills.Overfills are especially damaging to the equipment.Which process capability index would this company most want to monitor?

A system governed only by common causes is called a stable system.

Define and give an example of the three components of any control system.

Special cause variation tends to be easily detectable using statistical methods.

If process quality approaches six sigma levels, then standard types of control charts are not useful.

An operator has determined what her percent defectives is for the machine which she operates.Based on several samples of 75 observations, she found p-bar to be 10%.She wants to set up a control chart using 3 standard deviation control limits. a.What is the upper control limit for a p chart? b.What is the lower control limit for a p chart?