How many defects per million opportunities are there?
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Defects per Million Opportunities factors in the total opportunities for defect occurrence existing in a process. DPMO is considered long-term measurement of a process and this can be directly converted into a long-term z-statistic (sigma value) Show
Given: D: # of defects O: # of opportunities for a defect U: # of units TOP: Total number of opportunities = U * O Formula: DPMO = DPO * 1,000,000 DPO = Defects per Opportunity DPU = Defects per Unit See the links or the example below to help understand the differences. NOTE: DPMO is NOT the same as PPM (parts per million) since it is possible that each unit (part) being appraised may be found to have multiple defects of the same type or may have multiple types of defects. A part is defective if it has one or more defects. The number of defectives can never exceed the number of defects. IF each part only has one characteristic that can be a defect, then DPMO and PPM will be the same. You could have 1,000,000 defects on one part and the DPMO could be 1,000,000 and the PPM is 1.0 if that part is the only part out of the million that has any defects (in other words the other 999,999 parts have 0 defects). This is an exaggeration to try and illustrate the difference between DPMO and PPM. Also keep in mind that it's possible that each widget being measured (or assessed) has a different amount of potential defects. So theoretically you could have just a few widgets (very complex widgets) that have thousands of opportunities for defects or a lot of simple widgets that only have a few total opportunities for defects. PPM represents the number of defective parts (units) per 1 million units DPMO is the number of defects per 1 million opportunities of defects DPMO ExampleExamine the table shown below: Nail #1 has two types of defects. Therefore it is ONE defective nail that contains TWO defects.  SUMMARY OF TABLED = 19 total defects O = 5 opportunities (categories of defect types) U = 10 nails TOP = U * O = 50 total opportunities for defects DPU = D / U = 19/10 = 1.9 defects per unit DPO = D / TOP = 19/50 = 0.38 DPMO = 380,000 Out of a million opportunities, the long-term performance of the process would create 380,000 defects. Notice that only Nail #3 and Nail #9 had zero defects. Therefore 8 out of 10 nails had at least one defect. That represents a PPM of 800,000. Want to convert a DPMO of 380,000 to a z-score? Read below or click here to learn more about z-scores. Using Excel to calculate Sigma and DPMOThere are a couple commonly used Microsoft Excel functions that converts Defects per Million Opportunities (DPMO) to a process sigma (z-score) and vice versa. To convert from DPMO to process sigma:
To convert DPMO to % Defective
NOTE: A Six Sigma quality process refers to the process short-term performance or how it is performing currently when there are 3.4 DPMO. Over the long term, this six sigma process is estimated to shift -1.5 sigma (lower) and will perform at a 4.5 sigma level, which produces 1,350 DPMO. DPMO Calculator (Six Sigma Calculator)Enter your values in the white cells and everything else is calculated. Notes are in the actual template that offer more guidance and information on each row. This calculator can give you a ZST (if you input a shift of +1.5) or ZLT score (if the shift is 0). This is shown at the bottom as the 'Process Sigma' value. DPMO (and more) Calculator available for your Six Sigma project Search Six Sigma related jobs Sample certification problems Return to the Six-Sigma-Material Home Page Recent Articles
How many defects are there in a million?How do you calculate DPMO? It is the total number of defects in a sample divided by the sample size times the number of possible defects that you can have in an item. Multiply that by 1,000,000, and you get DPMO.
How do you calculate defects per million opportunities?Calculating Defects per Million Opportunities
First, find your total opportunities by multiplying the # of units by the # of defect opportunities per unit, then divide defects by your total opportunities then multiply by one million.
What does 3.4 defects per million opportunities mean?The term implies high-quality performance because a process performing at a Six Sigma level allows only 3.4 defects per one million opportunities. The higher the sigma level the better the quality of the product or service and the fewer the defects.
Why are there defects per million opportunities?DPMO stands for defects per million opportunities. It's a measure of process performance used to assess the quality of a process - e.g., the quality of a service or production. The lower the value of DPMO, the better, as it is tied with the probability of the presence of a defect.
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