In our case PPM means how many pieces of scrap are in one million produced part. This is quality index what we recognised in Knorr-Bremse supplier audit in 1999. The lower the PPM number is, the better. At that time this kind of measurement method was not widely used. Knorr-Bremse saw the development possibility, the willingness and talent in us to become A category supplier. This happened 3 years later. We could not forget this story, when stepped forward and we got to know the qualitative indices. Now we know well: ppm=0.