# Control Limits

Not what you're looking for?

Assume that you are the Quality Manager for the Emerson D. Meritz Machine Tool Company. Your model IE566 grinding machine is afflicted by three types of defects classified as major (type A), serious (type B) and minor (type C). You wish to set up a demerit system for this product using the following weighting scheme:

D=100 xa +50 xb +xc

where xa, xb, and xc are the number of the corresponding defect types observed on a single grinding machine. Based on past history xa, xb, and xc are known to be poisson distributed with means ca=5, cb=10 and cc=20.

I. Determine the center line and upper and lower control limits for the weighted number of demerits D observed on a single machine.

II. Using Minitab or other statistical software of your choosing, simulate 30 sets of observations of xa, xb, and xc and compute D for each set. Plot the D values on the control chart determined above.

III. Use the moving range of the D values found in item II to estimate the standard deviation of D. Compare it to the theoretical value of the standard deviation of D you computed in item I above.

IV. Using the approximate normality of D compute b and the ARL if the poisson means change to ca=10, cb=15 and cc=4

##### Purchase this Solution

##### Solution Summary

The expert examines the control limits for quality managers. Three types of defects classified as major, serious and minor are determined.

##### Solution Preview

II. Note the 30 values for xa,xb and xc are generated in excel. To do this : go to "tools > data analysis> random number generator> select Poisson ...

###### Education

- BE, Bangalore University, India
- MS, University of Wisconsin-Madison

###### Recent Feedback

- "Your explanation to the answers were very helpful."
- "What does 1 and 0 means in the repair column?"
- "Went through all of the formulas, excellent work! This really helped me!"
- "try others as well please"
- "Thank you, this helped a lot. I was not sure how to plug in those numbers to a formula. This was a great help. Now I have to figure out how to explain cost of capital is used in net present value analysis, and how cost of capital is used in net present value analysis. This stuff gets confusing."

##### Purchase this Solution

##### Free BrainMass Quizzes

##### Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

##### Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

##### Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

##### Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.