MGMT 650 Week 7 Discussion - Employing the Normal Distribution
Employing the Normal Distribution
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Operations and production managers
... [Show More] often use the normal distribution as a probability model to forecast demand in order to determine inventory levels, manage the supply chain, control production and service processes, and perform quality assurance checks on products and services. The information gained from such statistical analyses help managers optimize resource allocation and reduce process time, which in turn often improves profit margins and customer satisfaction.
Based on your understanding of the characteristics of the normal distribution, examine the chart below. Process A standard deviation is .9, Process B standard deviation is 1.4, and the mean of both processes is 12. Contribute to our discussion by posting a response to ONE of the questions below.
1. Do either of the processes fit a normal distribution? Why or why not?
2. Which of the processes shows more variation? What does this mean practically?
3. If the product specification quality limits were 12 +/- 3, which of the processes more consistently meets specification? Explain why.
4. If the product specification quality limits were changed to 12 +/- 6, is quality loosening or tightening? Which process would benefit the most from this change?
5. Are there processes at your place of employ that you believe follow a normal distribution? If so, describe one. Why do you believe it is normal?
ANSWERS
Chau Tran
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Chau Tran posted Jul 1, 2019 3:34 PM
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1. Do either of the processes below fit a normal distribution? Why or why not?
Both the Processes A and B fit a normal distribution. Since the curves of the Processes A and B looks like bell-shaped and symmetric normal distribution fit to those processes.
2. Which of the processes shows more variation? What does this mean practically?
The process B shows more variation since the standard deviation of Process B (1.4) is larger than the standard deviation of the Process A (0.9). It means the spread of Process B is larger than that of Process A.
3. If the product specification quality limits were 12 +/- 3, which of the processes more consistently meets specification? Explain why. For Process A,
P [(12 – 3) < X < (12 + 3)] = P [–3 < (X – 12) < 3]
= P [–3/0.9 < (X – 12)/0.9 < 3/0.9]
= P [–3.33 < Z < 3.33]
= F (3.33) – F (–3.33)
= 0.9996 – 0.0004
= 0.9992
For Process B,
P [(12 – 3) < X < (12 + 3)] = P [–3 < (X – 12) < 3]
= P [–3/1.4 < (X – 12)/0.9 < 3/1.4]
= P [–2.14 < Z < 2.14]
= F (2.14) – F (–2.14)
= 0.9838 – 0.0162
= 0.9676
Since 0.9992 > 0.9676, Process A is more consistently meets specification.
4. If the product specification quality limits were changed to 12 +/- 6, is quality loosening or tightening? Which process would benefit the most from this change?
If the product specification quality limits were changed to 12
+/- 6, the quality is loosening. Because of both the processes now equally consistent to meet the specifications as,
P [(12 – 6) < X < (12 + 6)] = 1.0000
for both the processes. Therefore, Process A would benefit the most from this change.
5. Are there processes at your place of employment that you believe follow a normal distribution? If so, describe one. Why do you believe it is normal?
In the pharmaceutical company I am working, the dosage (in mg) of particular drug used in the manufacturing process of a pill follows a normal distribution in my opinion.
Since the variable under study dosage weight of the drug is continuous in nature and is distributed around the limits of a specified range (µ ± s). The number of pills manufactured per day is very large in number. So the dosage weight of the drug is normally distributed. [Show Less]