Asked by Marcell Randall on May 06, 2024

verifed

Verified

Examine the Statistical Process Control outputs below. Answer the following questions.
a. What is the sample size?
b. What is the number of samples?
c. What is the mean of sample 8; what is the range of sample 10?
d. Is this process in control? Explain-a simple Yes or No is insufficient.
e. What additional steps should the quality assurance team take?  Mean  Range  UCL (Upper control limit) 12.68561.0193 CL (Center line) 12.360.67 LCL (Lower control limit) 10.03440 Sample Number  Item 1  Item 2  Item 3 Item 4 Mean  Range  Sample 1 12.212.61212.112.2250.6 Sample 2 11.912.512.412.712.3750.8 Sample 3 1212.212.913.112.551.1 Sample 4 12.512.512.412.812.550.4 Sample 5 12.212.812.71212.4250.8 Sample 6 12.112.511.812.312.1750.7 Sample 7 12.312.412.812.412.4750.5 Sample 8 1212.112.412.212.1750.4 Sample 9 12.112.812.411.912.30.9 Sample 10 12.612.412.112.312.350.5\begin{array}{|l|l|l|l|l|l|l|}\hline&&\text { Mean } && \text { Range }\\\text { UCL (Upper control limit) }&&12.6856&&1.0193\\\hline\text { CL (Center line) }&&12.36&&0.67\\\text { LCL (Lower control limit) }&&10.0344&&0\\\text { Sample Number }&\text { Item 1 }&\text { Item 2 }&\text { Item 3}&\text { Item 4}&\text { Mean } & \text { Range }\\\hline \text { Sample 1 } & 12.2 & 12.6 & 12 & 12.1 & 12.225 & 0.6 \\\text { Sample 2 } & 11.9 & 12.5 & 12.4 & 12.7 & 12.375 & 0.8 \\\text { Sample 3 } & 12 & 12.2 & 12.9 & 13.1 & 12.55 & 1.1 \\\text { Sample 4 } & 12.5 & 12.5 & 12.4 & 12.8 & 12.55 & 0.4 \\\text { Sample 5 } & 12.2 & 12.8 & 12.7 & 12 & 12.425 & 0.8 \\\text { Sample 6 } & 12.1 & 12.5 & 11.8 & 12.3 & 12.175 & 0.7 \\\text { Sample 7 } & 12.3 & 12.4 & 12.8 & 12.4 & 12.475 & 0.5 \\\text { Sample 8 } & 12 & 12.1 & 12.4 & 12.2 & 12.175 & 0.4 \\\text { Sample 9 } & 12.1 & 12.8 & 12.4 & 11.9 & 12.3 & 0.9 \\\text { Sample 10 } & 12.6 & 12.4 & 12.1 & 12.3 & 12.35 & 0.5 \\\hline\end{array} UCL (Upper control limit)  CL (Center line)  LCL (Lower control limit)  Sample Number  Sample 1  Sample 2  Sample 3  Sample 4  Sample 5  Sample 6  Sample 7  Sample 8  Sample 9  Sample 10  Item 1 12.211.91212.512.212.112.31212.112.6 Mean 12.685612.3610.0344 Item 2 12.612.512.212.512.812.512.412.112.812.4 Item 31212.412.912.412.711.812.812.412.412.1 Range 1.01930.670 Item 412.112.713.112.81212.312.412.211.912.3 Mean 12.22512.37512.5512.5512.42512.17512.47512.17512.312.35 Range 0.60.81.10.40.80.70.50.40.90.5

Upper Control Limit

The highest value on a control chart that represents the boundary of acceptable variation for a process or quality measurement.

Center Line

In quality control charts, this line represents the average or mean value around which data points are expected to fluctuate.

Lower Control Limit

A statistical boundary in quality control processes, below which a process variation is considered non-random and indicative of a systemic issue needing correction.

  • Interpret the purpose and calculation methodology of quality control charts.
verifed

Verified Answer

SD
Sarah DouglasMay 07, 2024
Final Answer :
The sample size is 4; ten samples were taken. The mean of sample 8 is 12.175; the range of sample 10 is 0.5. This chart is built on 2-sigma limits, so the probability of a false signal is about 4.5%. The process is not in control-while all means are within limits, the range for sample 3 is too large. Investigate for assignable cause and eliminate that cause.