Problem 1- Following are the results of the inspection of 20 batches of a certain product. Each sample size was 500, and the number of nonconforming products (np) is shown for each sample.
|
Sample
|
n
|
np
|
|
1
|
500
|
4
|
|
2
|
500
|
5
|
|
3
|
500
|
3
|
|
4
|
500
|
5
|
|
5
|
500
|
5
|
|
6
|
500
|
7
|
|
7
|
500
|
5
|
|
8
|
500
|
7
|
|
9
|
500
|
8
|
|
10
|
500
|
10
|
|
11
|
500
|
8
|
|
12
|
500
|
10
|
|
13
|
500
|
9
|
|
14
|
500
|
11
|
|
15
|
500
|
12
|
|
16
|
500
|
12
|
|
17
|
500
|
14
|
|
18
|
500
|
15
|
|
19
|
500
|
18
|
|
20
|
500
|
16
|
1. Make a p-chart using the above data.
2. Does the process appear to be normal?
3. Are there any trends, etc.? (What does this chart seem to indicate?)
4. Revise the chart if needed.
Problem 2- A manufacturer of garden tractors kept the following data regarding non-conformities per unit for completed machines.
|
Unit
|
c
|
|
1
|
15
|
|
2
|
11
|
|
3
|
13
|
|
4
|
17
|
|
5
|
16
|
|
6
|
18
|
|
7
|
15
|
|
8
|
19
|
|
9
|
20
|
|
10
|
21
|
|
11
|
23
|
|
12
|
34
|
|
13
|
33
|
|
14
|
18
|
|
15
|
18
|
|
16
|
16
|
|
17
|
14
|
|
18
|
12
|
|
19
|
11
|
|
20
|
9
|
1. Construct a c Chart from the above data.
2. What do you think of the process?
3. Revise the chart if needed.
Problem 3- Is going to be series with 3 components 1 (0.85) , 2(0.85) , 3(0.85)
Calculate the Reliability of the following system.
Problem 4- Calculate the Reliability of the following system.
Problem 5- A 1000 hour test of 100 items yielded one failure at 5 hours, one failure at 8 hours, one failure at 100 hours, 3 failures at 120 hours, and five failures at 900 hours.
1. Calculate the failure rate.
2. What is the mean life of the product?
3. What is the availability of this equipment if MTTR = 100 Hours
Problem 6- List the seven quality tools.
Problem 7- One important quality parameter in a potato chips company is the weight of each bag of potato chips. Assume the customer wants each bag contain 12 +/- 0.5 oz. potato chips.
Use what you've learned from our class (Quality Tools class). Establish a specific Quality Assurance Plan to ensure customer requirements will be satisfied.
Please answer this question fully. The key elements in this quality assurance plan should include:
1. What quality characteristics should the company monitor?
2. How to gather the information of the quality characteristics?
3. What quality tool(s) should the company use to monitor these characteristics? and how?
4. What are some of the warning signs that will trigger the corrective or preventive actions?
5. How to perform corrective or preventive actions when needed? What type of quality tools can the company use? And how?
A flow chart (decision tree) may help you establish this quality plan.
Please answer this question with "Bullets" format so the company can follow your guidance.
Problem 8 - A quality inspector created a p control chart based on one month operation data (sample size n=100). The p chart this person created has Center = 0.20, UCL = 0.32 and LCL = 0.08.
What is the value of Center, UCL and LCL of the np control chart for this data set?
Problem 9 - Use the Agresti and Coull (please refer to page 3 of "P chart article")method, calculate the UCL and LCL of the following data set (please note this is the example 1 data set from "P chart examples").
|
n - Sample size
|
np - No. of Nonconforming
|
|
500
|
20
|
|
500
|
21
|
|
500
|
19
|
|
500
|
15
|
|
500
|
18
|
|
500
|
20
|
|
500
|
19
|
|
500
|
28
|
|
500
|
17
|
|
500
|
20
|
|
500
|
19
|
|
500
|
18
|
|
500
|
10
|
|
500
|
11
|
|
500
|
10
|
|
500
|
9
|
|
500
|
10
|
|
500
|
11
|
|
500
|
9
|
|
500
|
8
|
For this problem, N=500, Z1-a/2=3 and Syi=15.6.