Your customer knows your PPM. Do you know which operation caused it?

Your OEM customer measures you in parts per million. He knows your rejection rate better than you do, because he is counting every one that reaches him.

Internally you know the monthly total. What you rarely know is which operation, which shift, which fixture produced it — which is the only level a corrective action can be written against.

In and out are recorded at every operation with the operator and shift, so a PPM number has an address.

An OEM supplier audit is not a surprise, but the preparation always is. Three people stop working for a week to assemble traceability, process records and corrective actions.

Everything exists. It is spread across registers, sheets and one person's laptop, and putting it together is the actual work.

Records are produced as the work happens, so preparing means filtering rather than assembling.

A line stops because a bin of components did not arrive from the previous operation, or from a vendor, or from stores.

It is logged as downtime. It is almost never logged as why, so the same interruption repeats next week and the week after.

Every stoppage now carries a reason chosen from your own list, so the pattern is visible in weeks not years.