First steps
- Classify suppliers by performance.
- Sampling plan per class.
- Reduce inspection where the supplier proves capability.
How to measure success
Inspection hours and escapes to the line. Record the value before you start, so the effect of every action can be shown.
When these methods are the wrong choice
- Acceptance sampling (AQL): Improving quality; it only sorts lots.
- Supplier scorecard: Selecting a new supplier.
- Supplier assessment: Day-to-day performance tracking; use the scorecard.
- PPAP: Internal process problems.
The methods in one line
| Method | What it is |
|---|---|
| Acceptance sampling (AQL) | Lot-by-lot sampling at incoming or final inspection with defined risks. |
| Supplier scorecard | Monthly rating of quality (PPM), delivery (OTD) and response, with classes A / B / C. |
| Supplier assessment | Scores a supplier’s capability by area with knock-outs, as self-assessment or on-site audit. |
| PPAP | Evidence package that the supplier’s process can make good parts at rate. |