Assignment:
1. You are the newly appointed assistant administrator at West Virginia University Hospital, and your first project is to investigate the quality of the patient meals put out by the food-service department. You conduced a 10-day survey by submitting a simple questionnaire to the 400 patients with each meal, asking them to simply check off the meal was either satisfactory of unsatisfactory. For simplicity in this problem, assume that the response was 1,000 returned questionnaires from the 1200 meals each day. The results are as follows:
|
Date
|
# of unsatisfied meals
|
Sample size
|
|
March 1
|
74
|
1,000
|
|
March 2
|
42
|
1,000
|
|
March 3
|
64
|
1,000
|
|
March 4
|
80
|
1,000
|
|
March 5
|
40
|
1,000
|
|
March 6
|
50
|
1,000
|
|
March 7
|
65
|
1,000
|
|
March 8
|
70
|
1,000
|
|
March 9
|
40
|
1,000
|
|
March 10
|
75
|
1,000
|
|
Total
|
600
|
10,000
|
(1) Construct a control chart based on the questionnaire results, using a confidence interval of 95.5% (i.e., 2 standard deviations).
(2) What comments can you make about the results of the survey?
2. The following table contains the measure of waiting time of severity index III(SI-III) patients in emergency room of NTC hospital for 20 consecutive days in February 2018. Everyday 5 SI-III patients were randomly picked and their waiting time was recorded.
(1) Construct a three-sigma X-bar chart and R-chart.
(2) What conclusion can we draw from the two control charts?
(3) If NTC hospital would like to benchmark with North Shore University Hospital whose average waiting time is close to 3 hours. What would you suggest as the focus of improvement initiative?
|
Day
|
P1
|
P2
|
P3
|
P4
|
P5
|
|
1
|
2.58
|
5.56
|
4.56
|
5.45
|
2.25
|
|
2
|
5.09
|
5.60
|
4.43
|
3.79
|
2.40
|
|
3
|
1.81
|
5.73
|
4.62
|
2.03
|
4.22
|
|
4
|
5.21
|
2.30
|
5.40
|
3.60
|
5.06
|
|
5
|
2.42
|
4.49
|
4.98
|
1.82
|
4.86
|
|
6
|
5.58
|
3.36
|
2.32
|
3.03
|
1.66
|
|
7
|
5.15
|
3.08
|
5.41
|
1.11
|
1.73
|
|
8
|
3.56
|
3.40
|
5.74
|
3.08
|
1.07
|
|
9
|
4.82
|
5.51
|
3.53
|
3.32
|
4.21
|
|
10
|
5.93
|
4.89
|
3.42
|
5.63
|
3.34
|
|
11
|
3.63
|
2.09
|
4.74
|
3.47
|
5.50
|
|
12
|
3.58
|
4.37
|
1.47
|
1.03
|
4.94
|
|
13
|
3.97
|
2.00
|
2.09
|
1.06
|
3.22
|
|
14
|
5.48
|
5.24
|
1.62
|
3.96
|
3.42
|
|
15
|
4.80
|
2.21
|
4.34
|
5.01
|
1.74
|
|
16
|
4.32
|
2.10
|
5.95
|
5.55
|
4.83
|
|
17
|
5.31
|
5.66
|
4.75
|
3.87
|
4.33
|
|
18
|
4.36
|
4.98
|
5.26
|
2.94
|
1.26
|
|
19
|
4.26
|
2.44
|
2.63
|
1.30
|
2.26
|
|
20
|
3.44
|
5.76
|
1.30
|
1.35
|
5.69
|