Question

Please answer each question set on a separate Excel worksheet, labeled appropriately. (Include all formulas)

Question Set 1.

You are in charge of quality control for computer monitors at Dell. You have data on twenty-five batches of monitors, tracking five types of defects: brightness, color, contrast, dead pixels, and stuck pixels. These data are given in the table below.

1. For each defect type, find the average number of defects per batch. So, you should have an average defect rate for brightness, another for color, and so on. (2pts)

2. For each batch, find the total number of defects (the sum of all five types). So, you should have one number for batch 1, another for batch 2, and so on. (2pts)

3. Sort the five columns of defects by descending average defect rate. The lowest rate should be on the right. (4pts)

4. Sort the batches by ascending total defects. The batch with the lowest total should be at the top. This will not affect the column sorting from the question 1.3 above. (4pts)

5. Create a Pareto chart showing the average defect rate for each of the five defect types. This will be a column chart, in descending left-to-right order, with each column and the axes labeled. (8pts)

	Defects
Batch	Brightness	Color	Contrast	Dead Pixels	Stuck Pixels
1	2	0	0	0	0
2	2	1	0	0	0
3	3	0	0	0	1
4	0	0	1	0	2
5	0	3	0	1	2
6	0	2	0	0	0
7	6	2	0	1	2
8	2	0	0	0	0
9	1	0	0	0	3
10	0	0	0	0	0
11	1	0	0	1	3
12	2	0	1	2	1
13	0	1	0	1	0
14	1	0	0	0	1
15	0	3	0	0	5
16	3	0	1	1	0
17	0	5	0	0	3
18	2	0	0	1	0
19	0	4	1	0	2
20	0	0	0	1	0
21	0	0	1	2	0
22	0	3	1	0	2
23	1	1	1	0	6
24	4	0	0	2	0
25	1	0	0	0	3

Question Set 2.

A manufacturing operation must periodically purchase bulk quantities of washers. The washers are purchased in boxes of 1000 and are consumed at a constant rate. The operation expects to purchase 20,000 boxes over the coming year. Each box costs $120, the annual holding cost per box is $15, and the cost of placing an order is $120 (regardless of the quantity ordered). For the following questions, use the basic economic order quantity model (without quantity discounts).

1. What is the economic order quantity (in boxes)? (2pts)

2. Calculate the annual inventory holding costs based on the average inventory level and annual holding cost per box. (2pts)

3. Calculate the annual inventory ordering costs based on the number of orders expected to be placed during the coming year. (2pts)

4. Create a data table showing the total inventory costs (only) for order quantities varying from 100 to 1200 (use a step size of 50). You must use a data table structure to receive full credit for this problem. If you have any doubt as to what a data table is, please ask your lab TA. (8pts)

5. Create a scatter chart (use the one with markers and smooth lines) showing how total inventory costs are a function of the order quantity. Be sure to label your axes appropriately. (6p

Answer 1

Question set 1

1

Please find the image below. Use the average formula as shown in the formula bar. =Average (B2:B26). Replace the column B with C, D, E, F for each of the defect types.

2

Please find the image below. Use the summation formula as shown in the formula bar. =Sum (B2:F2). Similarly replace do it for all the rows 2-26. So the final row will be =Sum (B26:F26).

3

The sorted columns are shown in the image below. This is a simple manipulation of column. There is no formula associated.

4

The sorted rows are shown in the image below. There is no formula associated. Select all the items between G2 and G26, right click and sort. Select ascending option and when prompted choose “expand with the selection”

5

In order to create Pareto chart. Create a separate table as shown. Add new columns for cumulative average defect and cumulative percentage. The last value of the cumulative average defect is the total defect. Calculate the percentage for each defect type by = Average defect rate/4.48*100

Next, use the insert chart function in order to create the Pareto chart. Shown below.