ABCDEFGHIJKLMNOPQRSTUVWXYZAAABACAD
1
2
Plotting X and R charts is required for a process. The measurements for the 25 samples are shown in the table.
3
The last two columns present the average of the sample X and the range R. The values ​​A2, D3 and D4,
4
were obtained from the surrogate measurement table.
5
6
7
Factors for the R chart
8
Sample numberObs 1Obs 2Obs 3Obs 4Obs 5XX BARLCLUCLRX BARLCLUCLNumber of observations in the subgroupFactor for X chartLower control limitUpper control limit
9
110,6010,4010,309,9010,2010,2810,219,8610,550,700,600,001,25756nA2D3D4
10
29,9810,2510,0510,2310,3310,1710,219,8610,550,350,600,001,25756
11
39,859,9010,2010,2510,1510,0710,219,8610,550,400,600,001,2575621,880,003,27
12
410,2010,1010,309,909,9510,0910,219,8610,550,400,600,001,2575631,020,002,57
13
510,3010,2010,2410,5010,3010,3110,219,8610,550,300,600,001,2575640,730,002,28
14
610,1010,3010,2010,309,9010,1610,219,8610,550,400,600,001,2575650,580,002,11
15
79,989,9010,2010,4010,1010,1210,219,8610,550,500,600,001,2575660,480,002,00
16
810,1010,3010,4010,2410,3010,2710,219,8610,550,300,600,001,2575670,420,081,92
17
910,3010,2010,6010,5010,1010,3410,219,8610,550,500,600,001,2575680,370,141,86
18
1010,3010,4010,5010,1010,2010,3010,219,8610,550,400,600,001,2575690,340,181,82
19
119,909,5010,2010,3010,3510,0510,219,8610,550,850,600,001,25756100,310,221,78
20
1210,1010,3610,509,809,9510,1410,219,8610,550,700,600,001,25756110,290,261,74
21
1310,2010,5010,7010,109,9010,2810,219,8610,550,800,600,001,25756120,270,281,72
22
1410,2010,6010,5010,3010,4010,4010,219,8610,550,400,600,001,25756130,250,311,69
23
1510,5410,3010,4010,5510,0010,3610,219,8610,550,550,600,001,25756140,240,331,67
24
1610,2010,6010,1510,0010,5010,2910,219,8610,550,600,600,001,25756150,220,351,65
25
1710,2010,4010,6010,8010,1010,4210,219,8610,550,700,600,001,25756160,210,361,64
26
189,909,509,9010,5010,009,9610,219,8610,551,000,600,001,25756170,200,381,62
27
1910,6010,3010,509,909,8010,2210,219,8610,550,800,600,001,25756180,190,391,61
28
2010,6010,4010,3010,4010,2010,3810,219,8610,550,400,600,001,25756190,190,401,60
29
219,909,6010,5010,1010,6010,1410,219,8610,551,000,600,001,25756200,180,411,59
30
229,9510,2010,5010,3010,2010,2310,219,8610,550,550,600,001,25756
31
2310,209,509,609,8010,309,8810,219,8610,550,800,600,001,25756
32
2410,3010,6010,309,909,8010,1810,219,8610,550,800,600,001,25756
33
259,9010,3010,609,9010,1010,1610,219,8610,550,700,600,001,25756
34
10,210,60
35
36
37
38
39
40
Upper control limit for X ̅=
UCL10,55
41
Lower control limit for X ̅=
LCL9,86
42
43
44
45
46
47
Upper control limit for R =
UCL1,25756
48
Lower control limit for R =
LCL0,00
49
50
51
52
53
54
55
56
57
58
59
60
61
62
The standard deviation as well as the Range will give an indication of the dispersion.
63
The Range is the difference between the maximum value and the minimum value of the observations in a sample.
64
65
66
When the R values fall below the central line, it indicates that the process at that point of time is having less dispersion that the average values of the same.
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100