How OEMs qualify suppliers: RFQ to production
SSG MFG engineering6 min read
How do OEMs qualify a new supplier for production parts?
OEMs qualify suppliers in stages: send an RFQ, evaluate quotes and capability, audit the quality system, approve sample parts, then approve production through PPAP or a first article inspection. Release follows a run at rate on production tooling. For a new tooled part, the full sequence typically takes 10–20 weeks, most of it tool build and sample approval.
What are the stages of supplier qualification?
Every OEM names the steps differently, but the sequence is close to universal. Each stage produces a document the next stage depends on, and skipping one usually shows up later as a quality problem.
| Stage | What happens | Typical duration | Deliverable |
|---|---|---|---|
| RFQ | Drawing, 3D model, quantities, and requirements go to 3–5 suppliers | 1–3 weeks to quote | Quotes with tooling, piece price, lead time, and exceptions |
| Evaluation | Capability, capacity, quality system, financial health, and logistics reviewed | 1–4 weeks | Supplier survey and audit report |
| Award | Tooling PO, DFM sign-off, tool design review | 1–2 weeks | Approved tool design |
| Tool build and samples | Tooling built, first shots or first pieces, adjustments | 4–16 weeks | Sample parts and initial dimensional report |
| PPAP or FAI | Product and process documented and approved | 1–4 weeks | Approved PSW or FAI report |
| Run at rate | Production run on production tooling at the quoted rate | 1–2 weeks | Production release and first production PO |
| Monitoring | Quality, delivery, and cost tracked | Ongoing | Scorecards and corrective actions (8D) |
What should an OEM look for in a supplier?
- Process capability: the right equipment for the part, such as press tonnage, machine envelope, and in-house secondary operations.
- Capacity: current utilization and shifts. Ask whether they can absorb your volume plus 20%.
- Quality system: ISO 9001 as a baseline; IATF 16949 for automotive, AS9100 for aerospace, ISO 13485 for medical devices, and ITAR registration for defense articles where the program requires it.
- Measurement: CMM, calibrated gauges, and measurement system analysis (MSA) on critical characteristics.
- Engineering support: DFM input and in-house tool design, which shorten sample loops.
- Financial stability and ownership: a supplier that fails mid-program costs more than any price difference.
- Communication: a named contact who answers technical questions within a day.
What is PPAP?
The Production Part Approval Process (PPAP) is the AIAG method automotive and many industrial OEMs use to confirm that a supplier understands every requirement and that its process makes conforming parts consistently at the quoted rate. It is the output of advanced product quality planning (APQP) and has 18 elements.
| # | Element | What it shows |
|---|---|---|
| 1 | Design records | The drawing and model at the approved revision |
| 2 | Engineering change documents | Any approved changes not yet on the drawing |
| 3 | Customer engineering approval | Engineering sign-off where required |
| 4 | Design FMEA | Design risks, if the supplier is design-responsible |
| 5 | Process flow diagram | Every step from receiving to shipping |
| 6 | Process FMEA | Process failure modes and controls |
| 7 | Control plan | What is checked, how, and how often |
| 8 | Measurement system analysis | Gauge R&R on critical characteristics |
| 9 | Dimensional results | Every drawing characteristic measured |
| 10 | Material and performance test results | Certs and test reports against spec |
| 11 | Initial process studies | Capability (Ppk) on special characteristics |
| 12 | Qualified laboratory documentation | Scope and accreditation of the labs used |
| 13 | Appearance approval report | Color, texture, and gloss approval, if applicable |
| 14 | Sample production parts | Parts from the production process |
| 15 | Master sample | A retained, signed reference part |
| 16 | Checking aids | Fixtures and gauges used for inspection |
| 17 | Customer-specific requirements | Anything the OEM adds |
| 18 | Part submission warrant (PSW) | The signed summary declaring conformance |
- Level 1: PSW only (plus appearance approval if applicable).
- Level 2: PSW with product samples and limited supporting data.
- Level 3: PSW with product samples and complete supporting data. The default when none is specified.
- Level 4: PSW and other requirements as defined by the customer.
- Level 5: PSW with product samples and complete supporting data reviewed at the supplier's plant.
What is a first article inspection?
A first article inspection (FAI) is a complete, documented measurement of every characteristic on the drawing, taken on parts from the production process. Aerospace uses AS9102, which has three forms: part number accountability, product accountability (materials, special processes, and functional tests), and characteristic accountability. Outside aerospace, an FAI is usually a ballooned drawing with a dimensional report and material certs.
- New part or new supplier
- Design change that affects form, fit, or function
- Change in process, tooling, sub-supplier, or manufacturing location
- A lapse in production; AS9102 uses two years
What process capability do OEMs require?
Capability indices compare process spread to the tolerance. Ppk describes an initial or short study; Cpk describes a stable, ongoing process. Measurement comes first: if the gauge eats most of the tolerance, the capability number means little.
| Metric | Value | Typical interpretation |
|---|---|---|
| Initial Ppk | ≥1.67 | Acceptable for PPAP |
| Initial Ppk | 1.33–1.67 | May be acceptable with customer approval |
| Initial Ppk | <1.33 | Not acceptable; corrective action and containment |
| Ongoing Cpk | ≥1.33 | Common minimum for special characteristics |
| Gauge R&R | <10% of tolerance | Acceptable |
| Gauge R&R | 10–30% | May be acceptable depending on application |
| Gauge R&R | >30% | Not acceptable; fix the measurement system |
What happens at production release?
Release follows a significant production run. AIAG guidance calls for one to eight hours of production and at least 300 consecutive parts unless the customer specifies otherwise, using production tooling, gauges, operators, and cycle times. Parts from that run feed the PPAP data, the PSW is approved, and production orders begin.
- Scorecards: defect rate in parts per million (PPM), on-time delivery, and responsiveness.
- Requalification: annual layout inspection and material testing where the control plan calls for it.
- Change control: the supplier notifies the OEM and gets approval before changing process, material, sub-supplier, or location.
How long does it take to qualify a new supplier?
| Scenario | Typical time |
|---|---|
| Transfer of existing tooling, no design change | 4–8 weeks |
| New machined part, no hard tooling | 3–6 weeks |
| New single-cavity steel injection mold | 10–16 weeks |
| New progressive stamping die | 10–18 weeks |
| New die casting tool | 12–20 weeks |
| Offshore tooling, including sample shipping | Add 2–6 weeks |
How does SSG fit into supplier qualification?
Use the builder at /build to get an instant budgetary estimate and DFM feedback before the RFQ goes out, so the budget and design are realistic from the start. An SSG rep then routes the RFQ to principals that fit the process, volume, and certification the program requires, and coordinates samples, PPAP, and FAI questions through release. Independent reps can join the network at /network and bring their OEM customers' jobs.
