SPC Tools

Pp and Ppk Fallout Rates

Calculated Capability Ratio Pp Fallout
(both sides combined)
Ppk Fallout
(one side only)

0.50
0.60
0.70
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00

133,620
71,860
35,730
16,396
6,934
2,700
966
318
96
26
7
2
0.340
0.060
0.012
0.002

66,810
35,930
17,865
8,198
3,467
1,350
483
159
48
13
3
1
0.170
0.030
0.006
0.001

 

Control Chart Constants

X and R Control Charts     X and S Control Charts
n A2 D3 D4 d2

1
2
3
4
5
6
7
8
9
10
11
12

2.660
1.880
1.023
0.729
0.577
0.483
0.419
0.373
0.337
0.308
0.285
0.266

-
0
0
0
0
0
0.076
0.136
0.184
0.223
0.256
0.283

-
3.267
2.574
2.282
2.114
2.004
1.924
1.864
1.816
1.777
1.744
1.717

-
1.128
1.693
2.059
2.326
2.534
2.704
2.847
2.970
3.078
3.173
3.258

   
n A3 B3 B4 C4

10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25

0.975
0.927
0.886
0.850
0.817
0.789
0.763
0.739
0.718
0.698
0.680
0.663
0.647
0.633
0.619
0.606

0.284
0.321
0.354
0.382
0.406
0.428
0.448
0.466
0.482
0.497
0.510
0.523
0.534
0.545
0.555
0.565

1.716
1.679
1.646
1.618
1.594
1.572
1.552
1.534
1.518
1.503
1.490
1.477
1.466
1.455
1.445
1.435

0.9727
0.9754
0.9776
0.9794
0.9810
0.9823
0.9835
0.9845
0.9854
0.9862
0.9869
0.9876
0.9882
0.9887
0.9892
0.9896

 

Special Cause Rules

Empirical Rule

Capability Study

Capability Formulas