PPM

The standard:

The calculation is a simple but punishing ratio: 1,000,000/(units shipped in the period) multiplied by the number of defective parts reported in the period. Infuriatingly few defects can drive a company over the target of 500 PPM.

 

In addition to measuring customer-reported defects, Micro monitors and reports internal defects by department to help everyone understand the importance of performing better than the 500 PPM target.

 

Several layers of protection to assure quality are in place at Micro:

• Verification of the part revision ordered against the print on file starts the process;
• When a job is released for production, it is reviewed by quality and production management beforehand to make sure any issues are resolved;
• First article approval, in-process inspections of controlled dimensions at prescribed frequencies, and final inspection are required for every part processed.
• Final inspection involves sampling the completed lot at a specified quantity to achieve an appropriate AQL. Statistically, if there is a non-conformance Micro is likely to identify it and contain the parts internally;
• Supplier non-conformance is tracked, and suppliers are quickly replaced if they are non-responsive and/or chronically non-conforming;