Concept explainers
a)
To construct: A
Introduction: Quality is a measure of excellence or a state of being free from deficiencies, defects and important variations. It is obtained by consistent and strict commitment to certain standards to attain uniformity of a product to satisfy consumers’ requirement.
a)
Answer to Problem 12P
Explanation of Solution
Given information:
Sample | Mean | Sample | Mean | Sample | Mean | Sample | Mean |
1 | 3.86 | 11 | 3.88 | 21 | 3.84 | 31 | 3.88 |
2 | 3.90 | 12 | 3.86 | 22 | 3.82 | 32 | 3.76 |
3 | 3.83 | 13 | 3.88 | 23 | 3.89 | 33 | 3.83 |
4 | 3.81 | 14 | 3.81 | 24 | 3.86 | 34 | 3.77 |
5 | 3.84 | 15 | 3.83 | 25 | 3.88 | x35 | 3.86 |
6 | 3.83 | 16 | 3.86 | 26 | 3.90 | 36 | 3.80 |
7 | 3.87 | 17 | 3.82 | 27 | 3.81 | 37 | 3.84 |
8 | 3.88 | 18 | 3.86 | 28 | 3.86 | 38 | 3.79 |
9 | 3.84 | 19 | 3.84 | 29 | 3.98 | 39 | 3.85 |
10 | 3.80 | 20 | 3.87 | 30 | 3.96 |
Formula:
Calculation of control limits and construction of
Graph shows the plot for sample means with UCL and LCL values. It can be observed that some points are above the control limits. So, the process is out of control.
Hence, the process is not in control.
b)
To analyze: The data using median run test and up and down run test and conclude the results.
Introduction: Quality is a measure of excellence or a state of being free from deficiencies, defects and important variations. It is obtained by consistent and strict commitment to certain standards to attain uniformity of a product to satisfy consumers’ requirement.
b)
Answer to Problem 12P
Explanation of Solution
Given information:
Sample | Mean | Sample | Mean | Sample | Mean | Sample | Mean |
1 | 3.86 | 11 | 3.88 | 21 | 3.84 | 31 | 3.88 |
2 | 3.90 | 12 | 3.86 | 22 | 3.82 | 32 | 3.76 |
3 | 3.83 | 13 | 3.88 | 23 | 3.89 | 33 | 3.83 |
4 | 3.81 | 14 | 3.81 | 24 | 3.86 | 34 | 3.77 |
5 | 3.84 | 15 | 3.83 | 25 | 3.88 | x35 | 3.86 |
6 | 3.83 | 16 | 3.86 | 26 | 3.90 | 36 | 3.80 |
7 | 3.87 | 17 | 3.82 | 27 | 3.81 | 37 | 3.84 |
8 | 3.88 | 18 | 3.86 | 28 | 3.86 | 38 | 3.79 |
9 | 3.84 | 19 | 3.84 | 29 | 3.98 | 39 | 3.85 |
10 | 3.80 | 20 | 3.87 | 30 | 3.96 |
Formula:
Analysis of data:
To make analysis of data, the given data is compared with median 3.85 to make A/B and U/D.
Sample | A/B | Mean | U/D | Sample | A/B | Mean | U/D |
1 | A | 3.86 | - | 21 | B | 3.84 | D |
2 | A | 3.90 | U | 22 | B | 3.82 | D |
3 | B | 3.83 | D | 23 | A | 3.89 | U |
4 | B | 3.81 | D | 24 | A | 3.86 | D |
5 | B | 3.84 | U | 25 | A | 3.88 | U |
6 | B | 3.83 | D | 26 | A | 3.90 | U |
7 | A | 3.87 | U | 27 | B | 3.81 | D |
8 | A | 3.88 | U | 28 | A | 3.86 | U |
9 | B | 3.84 | D | 29 | A | 3.98 | U |
10 | B | 3.80 | D | 30 | A | 3.96 | D |
11 | A | 3.88 | U | 31 | A | 3.88 | D |
12 | A | 3.86 | D | 32 | B | 3.76 | D |
13 | A | 3.88 | U | 33 | B | 3.83 | U |
14 | B | 3.81 | D | 34 | B | 3.77 | D |
15 | B | 3.83 | U | 35 | A | 3.86 | U |
16 | A | 3.86 | U | 36 | B | 3.80 | D |
17 | B | 3.82 | D | 37 | B | 3.84 | U |
18 | A | 3.86 | U | 38 | B | 3.79 | D |
19 | B | 3.84 | D | 39 | B | 3.85 | U |
20 | A | 3.87 | U |
Sample 39 ties with the median and in order to maximize the Ztest statistics, the sample 39 is labeled as B. Therefore, the observed number of runs is 18.
Median run test:
Calculation of expected number of runs:
The expected number of runs is calculated by adding half of the total number of samples with 1 which gives 20.5.
Calculation of standard deviation:
Standard deviation is calculated by subtracting number of sample 39 from 1 and dividing the resultant by 4 and taking square for the value which yields 3.08.
The z factor for median is calculated by dividing the difference of 18 and 20.5 with 3.08 which yields -0.81 which is within the test statistics of ±2.
Up/Down Test:
The observed number of runs from the analysis is 29.
Calculation of expected number of runs:
The expected number of runs is calculated by subtracting the double of the number of samples 39 and subtracting from1 and dividing the resultant with 3 which gives 25.7.
Calculation of standard deviation:
Standard deviation is calculated by multiplying the number of samples with 16 and subtracting the resultant from 29 and then dividing the resulting value with 90 and taking square root which yields 2.57.
The z factor for median is calculated by dividing the difference of 29 and 25.7 with 2.57 which yields +1.28 which is within the test statistics of ±2.
Hence, the results of the median run test and up/down test is random and no non randomness is detected.
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Chapter 10 Solutions
OPERATIONS MANAGEMENT (LL) >CUSTOM<
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