Karim

Hopefully this will be of use to other lost souls who stumble upon this rather old thread.I am a statistics teacher and I use Stats: Modeling the Real World by Bock, Velleman, and De Veaux. I recommend the book highly if you want to understand basic statistics. They address the issue of required sample size in order to perform a t-test as…[Read more]

i think toyota also has six sigma programs for process improvement.

In the six sigma methologogy, DPMO –defect per million of opportunities helps to determine the capability of a process-It is the same as PPM-parts per million–
However, some would argue that when talking about PPM, you denote the idea if deffective pieces and only talk about parts.
Note that  in some methodology, some are talking about PPM,…[Read more]