Re: Confusion DPU, PPM & DPMO vs Sigma level
The problem is the inconsistency between forum members and between this forum and the ASQ one.
Some are saying that PPM can be for defects or defective parts. It is up to the compagny to decide. This where start the confusion.
It is look like the literature is not consistent.
Who says the right thing?
Example from the ASQ Black belt book p179:
Process produce 40,000
Three type of defects can occur
-Blurred printing:36
- wrong dimensions: 118
-Rolled end: 11
Total Number of defects: 165
DPU= 165/40,000 = 0.004125
PPM = DPU x 1,000,000 = 4125
RTY = e>-0.004125 = 0.996
DPMO
Opportunity
-Blurred printing: 1 => TOP = 40,000
-Wrong dimensions: 3 => TOP = 120,000
-Rolled end: 2 => TOP = 80,000
Grand TOP = 240,000
DPMO= DPU * 1,000,000 / 240,000 = 687.5