PPM, or parts per million, is the number of defective parts you would ship in every million, and it is the core number OEMs use to score supplier quality. A low PPM keeps you off the customer's radar; a rising PPM invites containment, controlled shipping, and lost business.
How PPM is calculated
PPM is defects divided by total parts shipped, multiplied by one million. Ship two defective parts out of 100,000 and your PPM is 20. Because the number scales to a million, even a handful of escapes on a high-volume program moves your score fast, which is why programs feeding a high-volume plant like the Kentucky Truck Plant watch it closely.
Why PPM controls your scorecard and your risk
OEMs use PPM as a running grade of your quality. A climbing PPM is often what triggers a formal concern, a request for an 8D, GP-12 containment, or controlled shipping. It also shapes sourcing decisions at the next program, so PPM is not just a quality metric, it is a commercial one.
How to reduce PPM
Reducing PPM comes down to keeping defects off the customer line and fixing their source. That means fast containment when something slips, 100% sorting to separate good from bad, real root-cause corrective action, and tighter inspection during launch when the risk of a spike is highest. Local support helps you react in hours instead of days. See third-party sorting and inspection.