Initial sample inspection report and PPAP
An initial sample inspection report, ISIR for short, documents the inspection of the first parts manufactured under series conditions and compares the nominal and actual values from the drawing. Series production may only start once the customer has approved the report and the samples.
Timo Waldhoff
Managing Director
Short answer
- Initial samples are parts manufactured entirely with series production equipment and under series conditions.
- The ISIR compares every characteristic on the drawing with the measured actual value.
- In the automotive industry, the ISIR is part of the production process and product approval (PPF) to VDA Volume 2, and in North America part of the PPAP to AIAG.
- Since the sixth edition of VDA Volume 2 (April 2020), there have been no fixed submission levels, and scope and documentation are agreed in advance.
- New sampling is due after a drawing change, a change of material or a relocation of production.
Anyone buying a new part made to drawing or changing supplier cannot avoid the initial sample inspection report. Series approval depends on this document, and it is not only due with the first order.
What is an initial sample?
An initial sample is a part manufactured entirely with series production equipment and under series conditions. It therefore comes from the same tool, the same machine and the same process that will later be used for series production. A prototype from the workshop does not count.
This is precisely where the value of the report lies. If the initial sample meets all characteristics, it is highly likely that the series will meet them too. However, this only applies as long as nothing changes in the process.
What does an initial sample inspection report contain?
At its core is a complete measurement. Every characteristic on the drawing is inspected on a part from series production, and for each characteristic the nominal value, tolerance and actual value are listed side by side. Plöckl Media Group, a service provider for sampling, describes the report as a record to DIN EN 9102, VDA or customer specification.
Depending on the part, further documentation is added to the dimensional inspection. The table shows the typical elements, compiled from Böllhoff (sampling documents by submission level) and PeakAvenue (changes in VDA Volume 2).
| Element | Content |
|---|---|
| Cover sheet | Part, drawing revision, reason for sampling, supplier, customer, number of samples |
| Dimensional inspection | every dimension on the drawing with nominal, tolerance and actual value |
| Material | material test or inspection document, for metals often an inspection certificate 3.1 to DIN EN 10204 |
| Surface | coating thickness, coating, corrosion testing if required |
| Function | for example tightening torque or breakaway torque for coated screws |
| Process documentation | depending on the agreement, process FMEA, control plan, process capability, list of inspection equipment |
| Approval | customer decision with name, date and signature |
Not every line is required in every report. The customer specifies what is needed in each case, and that is what the sampling coordination meeting before sampling is for, described further down in the process.
When is initial sampling due?
Whenever something changes that may affect the part. Sampling therefore does not only belong at the start of a supply relationship. The glossary of QUALITY Services & Wissen lists these occasions:
- a new part that has never been supplied to the customer
- a change to the drawing, the specification or the material
- a new manufacturing process, a new or modified tool or relocation to another site
- a change of supplier for raw material or critical components
- the correction of a defect that led to a complaint
- the resumption of production after a tool has been idle for a long time
For purchasing, the third point is particularly important. Anyone who changes the supplier or the plant usually needs a new approval. This also applies if nothing has changed on the drawing.
How sampling works
Coordinate, manufacture, inspect, submit, decide: sampling follows this sequence, and the first step happens before a single part has been manufactured.
Customer and supplier first define the scope, number of samples, required documentation and deadlines. Under VDA Volume 2, this sampling coordination meeting has been mandatory since the sixth edition. The supplier then produces the samples, with series tools, series material and in the series process. Dimensions, material, surface and function are measured and recorded.
The report and the physical samples are then sent to the customer, who can carry out their own verification inspections. The customer approves, approves with conditions or rejects. In the case of rejection, the supplier makes corrections and submits new samples, each time with a new report.
Once the part has been approved, the initial sample serves as the reference for all later deliveries.
How do ISIR, PPF and PPAP differ?
The ISIR is a document, PPF and PPAP are procedures. In everyday use, the three terms are often treated as the same, but they sit on different levels. The table puts them into context and adds DIN EN 9102 for aerospace.
| Term | What it is | Origin |
|---|---|---|
| ISIR | the report on the inspection of the initial samples | general, content to customer specification, VDA or DIN EN 9102 |
| PPF | production process and product approval, the entire approval procedure with process and product documentation | VDA Volume 2, German Association of the Automotive Industry (VDA) |
| PPAP | Production Part Approval Process, the North American counterpart to the PPF | AIAG, Automotive Industry Action Group |
| DIN EN 9102 | requirements for first article inspection in aerospace, current edition 2025-01 | European standard EN 9102:2024 |
In the automotive industry, depending on the customer, an initial sample inspection report is part of the PPF to VDA Volume 2 or part of the PPAP. There it is one element of the procedure, not the entire procedure.
Submission levels under VDA
VDA Volume 2 no longer has fixed submission levels. Up to the fifth edition, they governed which documents the supplier had to submit. They were abolished with the sixth edition of April 2020. Since then, the guideline has specified a fixed list of documentation, and the customer can mark additional items as required. The old levels nevertheless still appear in the supplier requirements of individual customers.
What an initial sample inspection report does not replace
The ISIR proves that the process can manufacture the part correctly. It does not prove that every later batch is in order. That is what ongoing inspection and the inspection document for the delivery are for, for example a test report 2.2 or an inspection certificate 3.1 to DIN EN 10204.
DIN EN ISO 16228, the standard for inspection documents for fasteners, also draws this line explicitly. It is not intended for applications that require other procedures such as initial samples.
How NORM+DREH handles this
At NORM+DREH, you receive approval samples with full documentation before approving series production. Within a series order, these samples are generally free of charge. Separate advance samples without a series order are quoted at an individual flat rate per component. This does not imply that tooling is always free of charge. So you check the first part before the series runs. Every incoming delivery is inspected in our own quality department in Velbert, certified to DIN EN ISO 9001 and DIN EN ISO 14001. We define which documentation belongs to the sampling together with the quotation. Send us your drawing and we will clarify the scope of sampling at the same time. More on inspection and documentation on the page Quality and inspection certificates.
Frequently asked questions about the initial sample inspection report
What does ISIR mean?
ISIR stands for initial sample inspection report, in German Erstmusterprüfbericht (EMPB). It documents the inspection of the first parts from series production and compares every characteristic on the drawing with the measured value.
What is the difference between ISIR and PPAP?
The ISIR is an inspection report. PPAP is the approval procedure of the North American automotive industry to AIAG and, in addition to the sample inspection, also covers process documentation. The European counterpart is the PPF to VDA Volume 2.
When does an initial sample inspection report have to be prepared again?
With every change that may affect the part, for example a new drawing, a different material, a new tool, a new site or a new raw material supplier. New samples are also submitted after a complaint and after a tool has been idle for a long time.
How many parts are needed for initial sampling?
Customer and supplier agree this in advance. Neither VDA Volume 2 nor PPAP prescribes a fixed number in general.
Is there a template for the initial sample inspection report?
Many customers specify their own form. In the automotive sector, the structure follows VDA Volume 2 or the AIAG PPAP manual, in aerospace DIN EN 9102.