Layered process audit vs process audit
Short answer
A layered process audit (LPA) is a short, frequent check by managers at every level that the defined standard is being followed at a station: 10 to 15 minutes, yes / no questions, every shift to monthly. A process audit such as VDA 6.3 is a deep, scored assessment by a trained auditor of whether the whole process is planned, capable and robust: one or more days, once a year or when triggered. They complement each other, an LPA does not replace a process audit.
Side by side
| Aspect | Layered process audit (LPA) | Process audit (VDA 6.3) |
|---|---|---|
| Question it answers | Is the standard followed today? | Is the process able to deliver good parts? |
| Duration | 10 to 15 minutes | One or more days |
| Frequency | Every shift (layer 1) to monthly (management) | Typically yearly, or after a complaint or change |
| Auditors | Team leaders, supervisors, managers, plant manager | Qualified process auditor, often external or from another site |
| Questions | About 10 station-specific yes / no checks | Standard question catalogue P2 to P7 with 10 / 8 / 6 / 4 / 0 points |
| Result | OK / NOK per item, immediate reaction | Overall result EG in %, grade A, B or C |
| Reference | AIAG CQI-8, customer-specific requirements | VDA 6.3, IATF 16949 9.2.2.3 |
Why you need both
A process audit can find that a reaction plan is well defined, but it cannot see whether it is followed on the night shift next Tuesday. An LPA sees exactly that, but it would never notice that the control plan misses a characteristic. Use the process audit to make the standard right and the LPA to keep it alive every day.
Linking the two
Feed findings from process audits into the LPA questions: if the audit found that error-proofing checks were skipped, add a question for it. In the other direction, repeated NOK items in the LPA are a good input for the next process audit or a root cause analysis.