Question

Statistical Process Control

T. Crews, Inc. has been contracted to make Foolio. The recipe calls for 100 milligrams of taurine in each 16-ounce bottle. To make sure that they are in compliance, T. Crews has pulled eight bottles of Foolio from its last eleven batches and tested them for taurine content. The data from these tests is below.

Use this data for questions 8 – 14.

Mg taurine per bottle
Batch	Bottle 1	Bottle 2	Bottle 3	Bottle 4	Bottle 5	Bottle 6	Bottle 7	Bottle 8
1	103.37	104.15	105.02	105.90	105.45	107.15	109.02	109.50
2	101.00	99.42	96.72	98.50	95.13	96.15	98.83	93.30
3	103.30	100.11	101.96	102.40	100.37	100.22	106.50	101.20
4	101.00	99.73	108.31	103.75	109.70	100.35	108.00	95.93
5	101.35	104.62	108.12	103.10	99.69	103.83	97.16	104.11
6	98.05	98.58	97.35	100.25	101.39	100.55	101.34	109.07
7	96.65	98.96	92.61	107.28	97.08	99.75	107.35	104.48
8	107.00	103.56	101.39	97.65	103.65	102.62	98.26	100.67
9	100.97	103.42	101.98	99.36	112.08	103.18	100.75	104.36
10	107.15	98.30	98.25	105.33	97.45	99.12	103.95	103.71
11	107.02	104.07	106.00	101.89	102.51	103.06	102.48	97.87

1. What is UCL_X-bar?

a. Less than 100.00

b. Between 100.00 and 102.00

c. Between 102.01 and 104.00

d. Between 104.01 and 106.00

e. Greater than 106.00

2. What is LCL_X-bar?

  a. Less than 96.00

b. Between 96.00 and 97.00

c. Between 97.01 and 98.00

d. Between 98.01 and 99.00

e. Greater than 99.00

3. All points on the X-bar chart are within the control limits.

	True
	False

4. Is this process considered in control?

a. Yes, because all points on the r-chart are within the control limits

b. Yes, because all points on the r-chart and x-bar chart are within the control limits

c. No, because points on the r-chart or x-bar chart are not within the control limits

d. No, because points on R chart are too close to average

5. When an activity has two precedent activities, its early start time is equal to:

a) The later of the two precedent activities’ “Early Start” times

b) The activity’s start time minus its duration

c) The earlier of the two precedent activities’ “Early Finish” times

d) The later of the two precedent activities’ “Early Finish” times

6. An obstacle to supply chain integration is

a) information sharing between partners

b) limited supply chain visibility

c) considering the capabilities of partners when creating new processes

d) joint investment between firms in a supply chain

Answer 1

Find A2,D3 and D4 from the table of control chart constants for sample size m=9

X-bar Chart:

R-chart

Q1: What is UCL of X-bar Chart ?

d. Between 104.01 and 106.00

Q2. What is LCLX-bar?

d. Between 98.01 and 99.00

Q3.All points on the X-bar chart are within the control limits.

False (Batch 1 and Batch 2 value of X-bar is outside the UCL and LCL)

Q4.Is this process considered in control?

c. No, because points on the r-chart or x-bar chart are not within the control limits. ((Batch 1 and Batch 2 value of X-bar is outside the UCL and LCL)

Q5.When an activity has two precedent activities, its early start time is equal to:

d) The later of the two precedent activities’ “Early Finish” times

Q6.An obstacle to supply chain integration is

b) limited supply chain visibility