Defects per million opportunities

Defects per million opportunities ( DPMO ) (English: " defects per million opportunities " ) is a common, particularly in Six Sigma unit, and denotes the number of defects or defective units per million considered one of the units taking into account all possible error of one unit ( failure modes ).

In contrast to the statement of defects per unit ( error / ppm) is at DPMO the number of possible faults per unit involved to make different complex units more comparable.

Examples

I. ) Example of mathematics: incandescent production ( with only one possible error per bulb ). At 3.4 DPMO come to light bulbs manufactured 1,000,000 3.4 faulty light bulbs. This corresponds to a distance between the mean and nearest tolerance limit of six statistical standard deviations, in characters: 6σ ( pronounced in English: Six Sigma).

II ) Example for Sinnverdeutlichung: electronics manufacturing.

A component with 2 solder joints was made ​​in error once at a terminal at 1,000,000 made ​​circuit boards:

( 1,000,000 * 1 Error ) / ( 1,000,000 * 2 Component failure modes ) = 0.5 DPMO

In contrast, a complex chip with solder 100 is fitted on a different printed circuit board. With 1,000,000 made ​​a PCB solder joint on a chip was faulty:

( 1,000,000 * 1 Error ) / ( 1,000,000 * 100 Component failure modes ) = 0.01 DPMO

Absolutely each one error per million (1 ppm) was made, but the process quality in the lower point is significantly better.

Use

DPMO is used as the unit of assessment in quality management, as well as in business process optimization, with 3.4 DPMO = 6 Sigma is used as the name definition for the Six Sigma methodology.