AVEVA™ Manufacturing Execution System 2023 R2

DPMO Chart

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The following table contains the formulas used to calculate CL, LCL, and UCL for a chart point.

The example in the table illustrates the control limits calculated for a sample size of 15.

Formula	Example
CL = * (1000000/num_defect_opp) LCL = – (3 * ) * (1000000/num_defect_opp) UCL = + (3 * ) * (1000000/num_defect_opp) where n is the actual sample size from the sample, and num_defect_opp is the number of defect opportunities configured for the characteristic. If LCL < 0, then LCL = 0; otherwise LCL	CL = 0.55224 * (1000000/1) = 552238.80597 LCL = (0.45378 – (3 * )) * (1000000/1) = –0.02339 * 1000000 = –23385.44958 LCL = 0 UCL = (0.55224 + (3 * )) * (1000000/1) = 1.12786 * 1000000 = 1127863.06152

Formula

Example

CL = * (1000000/num_defect_opp)

LCL = – (3 * ) * (1000000/num_defect_opp)

UCL = + (3 * ) * (1000000/num_defect_opp)

where n is the actual sample size from the sample, and num_defect_opp is the number of defect opportunities configured for the characteristic.

If LCL < 0, then LCL = 0; otherwise LCL

CL = 0.55224 * (1000000/1) = 552238.80597

LCL = (0.45378 – (3 * )) * (1000000/1) = –0.02339 * 1000000 = –23385.44958

LCL = 0

UCL = (0.55224 + (3 * )) * (1000000/1) = 1.12786 * 1000000 = 1127863.06152

The following table shows example control limits calculated for each chart point.

Label	Chart Point (Defects Per Million Oppor- tunities)	Count	Size	LCL	CL	UCL	Lower σ	Upper σ
1	200000	3	15	0	552238.8	1127863.06	184079.6	191874.75
2	888888.9	8	9	0	552238.8	1295366.52	184079.6	247709.24
3	666666.7	10	15	0	552238.8	1127863.06	184079.6	191874.75
4	400000	6	15	0	552238.8	1127863.06	184079.6	191874.75
5	133333.3	2	15	0	552238.8	1127863.06	184079.6	191874.75
6	550000	11	20	53733.58	552238.8	1050744.03	184079.6	166168.41
7	600000	9	15	0	552238.8	1127863.06	184079.6	191874.75
8	333333.3	5	15	0	552238.8	1127863.06	184079.6	191874.75
9	1333333.3	20	15	0	552238.8	1127863.06	184079.6	191874.75