Worked example
One part, followed from drawing to production line.
This is what a unified platform makes possible. APQP plans a part into production. DMAIC improves it once it is running. On one platform, the second can begin with the decisions and evidence established by the first.
Every figure below is sample data for one illustrative part. Nothing here reflects a real customer, a real programme, or a real result. Where a value is calculated, it is calculated properly from the sample inputs shown.
APQP — planning a part that does not exist yet
Five phases. A gate closes only when its evidence exists — not when someone ticks a box.
| Element | Evidence on record | Gate it closes |
|---|---|---|
| Design record | ✓ Drawing rev C, 2026-03-04 | Phase 2 |
| Process flow diagram | ✓ 14 operations | Phase 3 |
| PFMEA | ✓ 22 failure modes · highest RPN 96 | Phase 3 |
| Control Plan | ✓ 9 controlled characteristics | Phase 3 |
| Measurement System Analysis | ✓ Gauge R&R 8.4% of tolerance | Phase 4 |
| Initial process study | ✓ Ppk 1.72 · 125 pieces | Phase 4 |
| Part Submission Warrant | ✓ Signed by a person, 2026-05-19 | Phase 4 |
Phase 4 could not close until Gauge R&R was under 10% and the process study existed. That is the difference between a gate and a checkbox — and it is the reason the warrant means something when an auditor asks.
The part goes into production
APQP is finished. What it established travels with the part.
- Control Plan · 9 characteristics
- PFMEA · 22 failure modes
- Capability baseline · Ppk 1.72
- Gauge R&R · 8.4%
- Drawing rev C
Everything APQP established stays attached to the part. The improvement project that opens next does not begin with a blank measurement plan — it begins with the one the launch team already validated.
Traceability is the point. When the improvement project later reports a change against baseline, that baseline is the figure the launch team validated and the customer accepted at PPAP — held once, and still attached to the part.
DMAIC — the same part, eleven months later
Hole position has drifted. An improvement project opens on the part APQP planned.
Define did not need a scope workshop to identify the characteristic — the Control Plan already named hole position as controlled. Measure did not need a new gauge study — the 8.4% R&R from Phase 4 is still valid and on record.
| Characteristic | Source | Ppk / Cpk | Study size |
|---|---|---|---|
| Hole position 12.00 ±0.20 mm | APQP Phase 4 initial study | 1.72 | 125 |
| Hole position 12.00 ±0.20 mm | Production, current | 1.08 | 300 |
| Change against the validated baseline | −0.64 | — | |
The baseline is not an assumption. It is the number the launch team validated and the customer accepted, still attached to the part — which is what makes the drift a fact rather than an argument.