How EU buyers specify and verify part quality with Balkan suppliers: drawings, qualification, first article inspection, AQL sampling, corrective action.
Part quality with a Balkan supplier is ensured the same way it is ensured anywhere: with a drawing that leaves nothing open to interpretation, and a documented chain of verification running from supplier qualification through first article approval to the paperwork on every shipment. Certificates do not make conforming parts; specified acceptance criteria and recorded measurements do.
The distance between a plant in Novi Sad and a receiving dock in Stuttgart is about one day by truck, so problems can be caught and closed inside a week rather than a quarter. That only pays off if the control points are defined in advance: a short feedback loop is useless when nobody is measuring anything.
Key takeaways
- ISO 9001 is a quality management system standard. It does not certify that a part conforms to its drawing.
- Ambiguity in a drawing becomes a commercial dispute later, so critical characteristics, datums, finish and permitted material equivalents belong on the print before the request for quotation.
- A first article inspection report is useful only if it is ballooned, complete and approved explicitly in writing before serial release.
- AQL sampling under ISO 2859-1 is a lot acceptance rule, not a guarantee that a passed lot is defect free.
- EN 10204 defines the types of inspection document for metallic products; type 3.1 covers specific inspection results on the delivered material.
- A corrective action closes on evidence, not when the 8D report is submitted.
- Change control in the purchase terms stops a supplier silently switching material, process or sub-supplier.
Contents
- Key takeaways
- Quality starts in the drawing
- Qualifying a supplier before the first order
- First article inspection
- Sampling and inspection during production
- Documentation that travels with the shipment
- Handling nonconformity when it happens
- Keeping quality stable over time
- Frequently asked questions
- Where to go next
Quality starts in the drawing
Most quality failures are specification failures: the supplier made what the drawing allowed, and the drawing allowed something the buyer did not want. A technical package that can be inspected objectively is the first control.
What a complete technical package contains
Use GD&T (geometric dimensioning and tolerancing, per ISO 1101 or ASME Y14.5) so that form, orientation, location and runout are stated against a declared datum reference frame, not implied by dimension chains. Name the general tolerance class (from the ISO 2768 series, for example) and treat it as a fallback, not a substitute for tolerancing what matters.
Beyond dimensions, state: material and permitted equivalents; heat treatment condition with the hardness or case depth to be verified; coating type, thickness and the surfaces it covers; surface texture with parameter and value, not just a symbol; edge and burr condition (ISO 13715 covers exactly this); cleanliness for parts entering a fluid circuit or a clean assembly; marking and traceability; packaging.
Identify what is critical to function
Mark a small set of critical characteristics, the features whose deviation makes the part fail in your assembly. That tells the supplier where to concentrate process control and what belongs in every inspection report.
Qualifying a supplier before the first order
Supplier qualification tests capability, not intent: whether the shop can hold the tolerances, whether it can prove it did, and whether its management system survives an audit. Certification is the entry ticket; measurement capability decides whether the parts are good.
What the management system standards cover
ISO 9001 specifies requirements for a quality management system: a certified supplier has documented processes, competence and calibration control, records and a corrective action route. It certifies no product characteristic. IATF 16949 is the automotive sector standard, applied together with ISO 9001, adding defect prevention and supply chain discipline expectations including production part approval. ISO 13485 covers quality management systems for medical devices where regulatory requirements apply. Match the standard to the sector.
Measurement and process capability
Ask what the shop can measure and to what uncertainty: CMM (coordinate measuring machine) capacity, height and bore gauges, surface roughness testers, hardness testers, coating thickness measurement. Ask for calibration records traceable to national standards, and how they run MSA (measurement system analysis, typically gauge repeatability and reproducibility), so you know the gauge is not consuming the tolerance.
For repeat parts, ask about process capability indices such as Cp and Cpk on critical characteristics. These mean something only for a stable process with enough data, so a capability claim before the first order is an intention, not a result. Material traceability closes the loop: heat or batch numbers linking finished parts to the mill certificate. Our capabilities overview covers the process families involved.
First article inspection
FAI (first article inspection) is the formal check that a production process, using production tooling and material, makes a part meeting every requirement on the drawing. It runs before serial release, and its output is a report you approve or reject in writing.
What the FAI package must contain
| Item | Notes |
|---|---|
| Ballooned drawing | Every characteristic uniquely numbered, matching the results table |
| Dimensional results | Nominal, tolerance, actual, pass or fail; one row per balloon |
| Measurement method | The gauge or CMM programme used per characteristic |
| Material certificate | EN 10204 type 3.1 where specified |
| Heat treatment record | Condition and hardness against the drawing |
| Coating certificate | Type, thickness, test method; adhesion or salt spray if required |
| Special process records | Welding, brazing, passivation, with procedure references |
| Photographs | Several views, readable marking, packed condition |
| Traceability data | Machine, operator, date, batch |
| Signature and date | Supplier quality function, not sales |
In automotive supply chains the equivalent is PPAP (production part approval process), which adds the process flow, control plan, failure mode analysis and a part submission warrant. Aerospace uses AS9102 forms.
Approval must be explicit
Silence is not approval. Release serial production only against written first article approval naming the drawing revision it covers. If that revision, or the process, tooling or material changes, a new or partial first article is required. This discipline separates a controlled supply chain from a hopeful one, and it is where our process puts a hard gate.
Sampling and inspection during production
Serial quality is controlled by inspecting at defined points under defined rules, not by checking parts when someone feels uneasy. Three layers do the work: in-process checks by the supplier, a pre-shipment inspection, and an independent third-party inspection where the stakes justify one.
In-process control
The supplier should hold a control plan naming, for each operation, what is checked, how often, with what gauge, and what happens when a result falls out of limits. First-off approval at setup, periodic checks during the run and last-off retention are standard practice. Critical characteristics may warrant statistical process control charting rather than pass or fail checks alone.
Sampling plans and AQL
AQL (acceptance quality limit) sampling under ISO 2859-1 defines, for a given lot size and inspection level, how many pieces to inspect and the maximum defects allowed before the lot is rejected. It is an acceptance rule for inspection by attributes, so a lot that passes can still contain nonconforming parts. That is why critical characteristics are commonly inspected at a tighter AQL, at a higher level, or one hundred percent. Agree the plan and the defect classification (critical, major, minor) in the order, not after a rejection.
What a useful inspection report contains
An inspection report should state the order and part number, drawing revision, lot size, sample size and sampling standard, measured results against tolerance, defect classification and counts, equipment used, packaging and marking checks, an accept or reject conclusion, and dated photographs of the parts, the defects and the packed goods. A report without photographs or a stated sampling basis is an opinion.
Documentation that travels with the shipment
Every shipment should arrive with the evidence that makes it acceptable without a phone call. Which documents apply depends on the part and the sector, so define the list in the purchase order and treat a missing document as a nonconformity.
The usual set: the inspection report for the lot, material certificates (EN 10204 type 2.2 or 3.1 as specified), heat treatment and coating certificates with measured thicknesses, special process records, a declaration of conformity where one is required, and packing and traceability data linking cartons to batches. Origin documentation belongs in the same package for goods entering the EU under a preferential arrangement, covered in proof of origin under the Serbia and EU SAA.
Handling nonconformity when it happens
A nonconformity is handled in three stages: contain, find the cause, prove the fix. Skipping the third turns corrective action into a promise.
Containment comes first. Raise an NCR (nonconformance report) describing the deviation against the requirement, quarantine affected stock at your site and at the supplier, and bound the suspect population by batch and date. Only then decide disposition: use as is under a written concession, rework, sort or scrap.
8D (eight disciplines) is the common root cause framework: team, problem description, interim containment, root cause, corrective action, implementation, prevention of recurrence, closure. Inside it, 5 Why questioning and an Ishikawa (cause and effect) diagram separate the cause of the defect from the cause of the escape. A dimension drifted because a tool wore; it reached you because the control plan did not check it after setup.
CAPA (corrective and preventive action) is verifiable only when it names the changed document or control and states how the change is monitored. Ask for the updated control plan, data from the first lots after the change, and a defined verification window.
Keeping quality stable over time
Quality holds over years because the relationship is measured and changes are controlled, not because the first order went well. Two mechanisms carry the weight: a supplier scorecard and a change control clause.
Score suppliers on a few things you act on: on time delivery against the confirmed date, defect rates by lot or by piece, first pass yield at incoming inspection, documentation completeness, responsiveness on corrective actions. Review it on a fixed cadence and let it drive the audit interval, inspection level and volume allocation.
Change control is the clause buyers most often forget. Require written notification and approval before any change of material, process, tooling, production location or sub-supplier, and require a new first article afterwards. Without it, a supplier can move an operation to a second shop or swap a plating vendor while every dimension still passes, and you find out from a field failure. Our quality methodology describes how these gates apply to orders we place.
Frequently asked questions
Is ISO 9001 certification enough to guarantee good parts?
No. ISO 9001 is a quality management system standard: it shows the supplier has documented processes, records, calibration control and a corrective action route. It certifies nothing about whether a given part meets a given tolerance. Verify conformity separately, through first article inspection, in-process control and pre-shipment inspection.
What should a first article inspection report include?
A ballooned drawing with every characteristic uniquely numbered, a results table giving nominal value, tolerance, actual measurement and pass or fail for each one, the measurement method used, material, heat treatment and coating records, and photographs. It should also record machine, operator and date.
What does AQL sampling actually tell you?
AQL sampling, defined in ISO 2859-1, sets how many pieces to draw from a lot and how many defects are allowed before the lot is rejected. It is a statistical acceptance rule for inspection by attributes, not a measurement of the true defect rate.
What is the difference between EN 10204 type 2.2 and type 3.1?
EN 10204 defines types of inspection document for metallic products. A type 2.2 test report gives results of non-specific inspection, meaning results not taken from the delivered batch. A type 3.1 inspection certificate gives results of specific inspection on the delivered material, validated by an inspection representative independent of manufacturing.
How do you ensure quality from a supplier you cannot visit often?
Put the verification in writing rather than in visits. Agree acceptance criteria before production, require an approved first article before serial release, define the sampling plan and the pre-shipment check, require documentation with every shipment, and add an independent third-party inspection for a new supplier.
How do you make a corrective action verifiable instead of a promise?
Require the 8D report to name the changed document, setting or control, and to state how the change is monitored. Then ask for evidence: the revised control plan, dimensional data from the first lots after the change, and a defined verification period. Close the nonconformance on that evidence.
Where to go next
Our quality methodology sets out the control points we apply to orders. For a part quoted with acceptance criteria and inspection requirements defined up front, send the drawing. To discuss a standard, sampling plan or documentation set, get in touch.