Q 1

Q 1 A restaurant Manager is concerned about the temperature of the food items being served. He never wanted the food to be warmer than 160 degree F and cooler than 147 degree F. He decided to do a study of the samples for 10 days and collected three servings and recorded the temperatures. Following is the samples and the readings Sample no Readings

1. 150160155

2. 140150155

3. 145150150

4. 150150155

5. 130155150

6. 140140145

7. 150150150

8. 155155160

9. 160160160

10. 150160165

The following values are given Sample sizeD3D4A2

203.2671.880

302.5751.023

402.2820.729

Develop charts and comment on the process .

Q2. A control Chart for fraction non conforming is to be established with the centre line at 0.07 (p=0.07).How large the sample size should be to so as to have a non zero value of LCL.

Q 3. A company produces micro-oven components on mass basis. At some production point 10 samples of 100 each were collected . They were categorized as Good or Defective ., and the number of defectives were as follows: 18,19,8,15,17,12,19,1, 15, 17. Construct a p chart with 3 sigma limits and comment on the process . Q4. A company produces chips on mass production basis. At some production point 10 samples of 50 each were collected and the no. of defects found were as follows: 9,10,4,9,8,6,9,8,7,5 . Construct a p chart with 3 sigma limits and comment on the process .Q 5. Control chart for mean and range are to be set up on the measurements of diameter of a shaft . Samples were of size 4. After 30 samples were taken it was found that the mean value of dias were 7515 . The mean value of ranges were 360. The customer wanted that the diameter of the shafts should be within 250mm +/- 10mm. It is given that for n=4, A2 =0.729, D3= 0, D4= 2.282.Determine the control limits . What is the probability of rejection by customer ?

Q6. Forecast for the month Feb =100 units. Actual demand for Feb is 90. if alpha = 0.12, what should be forecast for March ?Q7. The data given in the table are the timestudy in an operation of existing two elements :

Element 1 :

0.140.140.150.150.180.200.190.170.170.180.14

0.150.190.170.130.140.170.180.170.160.160.14

Element 2 :

0.090.060.050.060.070.060.060.060.070.090.07

0.060.070.070.080.070.070.070.060.060.060.07

During the time study the 1st element was rated as 90% and second at 120% .Total allowance to be given for the operation is fixed at 12%. Determine the standard time for the operation.Q 8. ABC company purchases metal bars , for which annual demand is 4500 units. It requires Rs 75 to place one order . The interest cost is 18% per anum and other costs for holding inventory is 7% per anum. The price in the market is as below :

Unit Price/ Rs unit

1-299 60

300-499 50

500 40

and more

What is the optimum quantity of order with this price break ?

Q9. A company uses packages of plastic tapes to create layouts . About 200 packages are consumed each year . The supplier gives quantity discount as follows

Unit Price/ Rs unit

1-99 100

100- 499 95

500 90

and more

if the company has a 35% carrying cost per year and spends about Rs 300 per order determine the right order quantity.

Q 10 A print shop company manufactures its own envelops . For a production rate of 2000/hour the set up cost is Rs 7500. Average demand for envelopes is 10,000 per month.Annual cost for holding inventory is 15%. Envelopes cost Rs 500/ 1000 units in the market. A working months average is 160 hours.

a) what is the economic production quantity in months supply ?

b) If the company buys the envelopes , and the order processing cost is Rs 500 , what should be the optimum order quantity?

c) If the set up time is 2 days , what is the reorder point ?

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