SPC Question Paper

Name:

Examination - SPC

Date:

Total Allowed Time :1.5 Hours

1. It was found that in a lot of 500 Air Conditioners , there were 7 brazing leakage cases found. If there are 45 brazing joints in each air conditioner, find out DPU, DPO & Yield of Brazing process.

2. Write the name of all type of control chart & for any two write the appropriate application of use.

3. At X-Bar Total = 135.67 & R Total = 21.6, What would be the value of X-Bar UCL Given that Total Subgroups are 20 & Subgroup size is 5

4. a) b)

Conduct the X-Bar R Chart for the following data & answer the below From the R Chart, find out the UCL R Value At CL 18, what would be the UCL X-Bar Value

1

2

3

4

20.1 19.8 19.5 20.4 20.1

20.1 19.8 20.3 19.4 19.5

20.1 20.4 20.5 19.5 20.3

19.9 21.2 20.3 20.4 19.7

5. Calculate the standard deviation for the data points given in the below 10 data 1

2

20.1 19.8 19.5 20.4 20.1

20.1 19.8 20.3 19.4 19.5

Name:

Examination - SPC Q6.

Q7.

Date:

Total Allowed Time :1.5 Hours

Which is the wrong explaination of the following a) U Chart charts the no. of defects per unit sampled in each subgroup. Use U Chart when the subgroup size varies b) P Chart charts the proportion of defectives in each subgroup c) NP Chart charts the number of defectives in each subgroup d) C Chart charts the no. of defects in each subgroup. Use C Chart when the subgroup size varies e) None of these

Which type of the following charts can be used for attribute data a) n Chart b) X-Bar R chart c) U Chart d) X-Bar S Chart

Find out which control chart should be used when given no. of defectives & sample size is constant a) p Chart b) C Chart c) np Chart d) U Chart

Q8.

Q9.

Find out which is the wrong explaination for the concept of process stable a) We can conclude the process is stable if the process output is consistent with common cause. b) Stability means the average and range are located within control limits c) If there are any pt outside the control limits then we must accept that the process is not stable d) To estimate the process, it is not necessay that process should be stable

Q10.

The followings are explanation of continous control chart. Find out 2 wrong answers. 1) If the subgroup size is 5 , Xbar & R control chart will be better than I&M R control chart. 2) The UCL & LCL can be considered as specification limit 3) If 2 points among 3 consecutive ones are out of 3sigma , it can be considered as unstable condition. 4) To stabilize the condition, all the points in control chart shall be within ±1σ.

Q- 11 Refer to the table given , calculate the CL, LCL UCL for an appropriate control chart, sampling size/ subgroup size is 5.

Sampling No. 1 2 3 4 5 6 7 8 9 10

Number of Errors 21 24 16 12 15 5 28 20 31 25

Name:

Examination - SPC

Total Allowed Time :1.5 Hours

Date: