What is PPM?

(Parts per million)

PPM (Parts per million) is a measurement used today by many customers to measure quality performance.

Definition: One PPM means one (defect or event) in a million or 1/1,000,000

There was a time when you were considered a pretty good supplier when your defect rate was less than 1%, (10,000 PPM), then the expectation was increased to 0.1% or 1,000 PPM. Now the rate for most automotive components is targeted at 25 PPM or 0.0025%

To calculate: For example, let's say you had 25 pieces defective in a shipment of 1,000 pieces. 25/1000= .025 or 2.5% defective. .025 X 1,000,000 = 25,000 PPM.

Let's put it in perspective. Let's say, you produce 10,000,000 parts per year for your customer. If you're like most companies, your plant operates around 5 days a week, 50 weeks per year or 250 days a year. Let's assume your customers requirements are 25 PPM. That means that you would be allowed 25 pieces for every 1,000,000 pieces or 250 defective parts per year. Or to put it another way, one bad part per day! Notice I did not say one bad part per day per person or job, or shift or machine. One bad part for the entire plant for 24 hours!

Impossible? Yes if you are still using the same manufacturing methods which were responsible for the 5 or 10% scrap you used to accept.

A friend of mine had the following quotation on his wall:

Insanity is doing things the same way we've always done them and expecting different results. 

The monitoring and measurement systems we have today have paved the way for improved quality. We can now control the process in order to control the quality. Quality can not be inspected in after the fact. It is the result of careful planning, design, and execution.

If you don't measure it you can not control it.

If you would like to learn how to reduce your PPM while increasing profits I can help.

First by demonstrating a systematic and scientific approach to design and manufacturing in your facility.

Second, by training your personnel in the use of the tools and methodology.

Click the following for information on consulting and training services offered by McClintic & Associates.

 

Other technical articles on die casting by Bob McClintic

Bob McClintic and Associates

Grand Rapids, Michigan 49534 USA

Office: 616-292-0454

E-mail: RMcClintic@DrDieCast.com

 Copyright Bob McClintic and Associates: 2024

Revised: June 27, 2024