Sampling (technology)
In production and manufacturing technology, as well as in the associated quality management, sampling is understood to be the testing of components or finished products for compliance with specified properties . A distinction is made between initial sampling and subsequent sampling.
Initial sampling
With the initial sampling, the supplier provides evidence that his products meet the quality requirements demanded by the customer. The abbreviation FAI (First Article Inspection), which comes from the English, is also often used.
Definition of initial samples and initial sample testing
The Aalen University of Applied Sciences defines as follows:
- An initial sample is a product that was first produced under series production conditions.
- This initial sample is usually subjected to a full inspection in order to prevent errors from the start of series production and to check whether agreements have been adhered to.
- The procedure for the initial sample inspection is specified with the supplier in the quality assurance agreement. If you use a standardized report form, the supplier enters target and actual values with deviations in the tested parts. The customer can then request further tests or carry them out himself.
- For the customer, the initial sample inspection is the first opportunity to inspect the quality of the delivery ordered.
Similar to the definition of a commercial enterprise, here Magna Powertrain :
- Initial samples are products that have been completely manufactured using standard equipment and under standard conditions. Sampling with initial samples is called initial sample testing. The sampling for the production process and product approval must be carried out with initial samples. The positive evaluation of the initial sample (including documentation) by the customer results in the approval of the supplier series process.
Essential characteristics of an initial sample
The first essential feature of an initial sample test, which both definitions mention, is the first-time production of the goods to be sampled under the realistic conditions of series production . Both definitions, however, leave open whether the production process itself is to be subjected to a process capability test or to be examined using another test procedure .
The second essential feature of an initial sample test, which both definitions mention, is the subsequent test of the first sample produced in this way with regard to the technical and non-technical properties of the product required and agreed by the customer . The definition of the test methods is also left open here.
The first definition assumes that initial sample tests only take place on the basis of a quality assurance agreement, which does not necessarily have to be the case in reality, since the obligation to perform initial sample tests is also part of another contractual agreement (e.g. a sales contract , supply contract , Framework supply contract, or a non-disclosure agreement ).
The second definition contains two further, essential characteristics of initial sample tests, namely the need for documentation and the approval of the supplier by the customer if the initial sample test has been passed.
Initial sampling in the automotive industry
Initial sampling is common in the automotive industry and can be carried out according to various standards . By regulations such as the ATF 16949 and PPF / PPAP some standardization in the handling of product sampling in the automotive industry and a close cooperation between customer and supplier is reached, thus creating a basis for agreements. The main regulations are described in the following paragraph.
Initial sampling according to IATF16949, PPAP and PPF
IATF 16949 defines requirements for sampling according to the so-called Production Part Approval Process (PPAP) according to the reference manual of the Automotive Industry Action Group (AIAG).
Accordingly, today u. a. Sampling ( acceptance , approval) according to PPAP or production process and product approval (PPF) according to VDA Volume 2 (for users of VDA Volume 6.1) is common, whereby the Association of the Automotive Industry (VDA) points out in the foreword to Volume 2 that the PPAP requirements have been taken into account. The PPAP reference manual contains requirements, while the VDA Volume 2 specifies PPF guidelines according to certain principles , which describe the handling of new parts.
In principle, it is necessary to provide evidence that the supplier has understood the requirements and carried out quality planning and can meet the customer's expectations under standard conditions.
The application of the PPAP / PPF process is relatively complex, since submission levels have to be defined, taken into account and recorded in special PPAP / PPF documents according to the customer-specific requirements during the production part acceptance. The associated reporting , verification and the associated possible stumbling blocks were further reasons why the International Automotive Sector Group (IASG) developed special interpretations of the PPAP process and the QS 9000 at the end of the 1990s .
The approval procedures according to VDA 2 (PPF) or AIAG (PPAP) include both the product and the production process approval.
Follow-up sampling
Subsequent sampling is understood as a new sampling when production is restarted. This can be done by the customer z. B. be required after a production interruption of several months in order to achieve a requalification of the corresponding component after the approval has expired.
Reduced initial sample inspection
In the case of follow-up sampling, one sometimes speaks of a renewed or reduced initial sampling, which is factually not entirely correct, since a follow-up sampling can never be an initial sampling. See also: Cover sheet sampling
Double sampling as follow-up sampling
In individual cases, the term follow-up sampling is also used for a renewed sampling, also called double sampling, which the customer does not want. Example: Double sampling disrupts the operational process and causes costs and delays and should therefore be avoided in principle. If there is a follow-up sampling due to non-compliance with customer specifications, the supplier will be charged the costs.
Cover sheet sampling
The term cover sheet sampling is an old name when the supplier only provides a cover sheet and no parts to the customer for initial sampling.
How and what the supplier should present to the customer for initial sampling is currently regulated in VDA Volume 2. In VDA Volume 2 (Production Process and Product Release / PPF, English = PPA) there are different submission levels 0, 1, 2, 3. A cover sheet must always be included in all submission levels. The details and contents of an initial sample must always be agreed between the customer and the supplier in advance.
Sampling of buildings (building sampling)
In the construction industry, sampling is referred to as "the meeting between supplier and house buyer that is customary in the prefabricated house sector (often in prefabricated house centers or exhibitions) with the aim of determining the exact furnishings of the house or apartment ." designated. In contrast to the sampling of industrial products, this sampling is part of the construction planning , not the construction .
Individual evidence
- ↑ Definition of initial samples and initial sample testing according to Aalen University of Applied Sciences Quality Management - The role of purchasing ( page can no longer be accessed , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Definition of initial samples according to the guidelines for the initial sample presentation at Magna Powertrain (MPT) ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 541 kB)
- ↑ GFQ Academy seminar description PPAP / PPF
- ↑ Interpretations recognized by the IASG on QS-9000: 1998, Third Edition and Quality Standards in the Automotive Industry - The QS 9000
- ↑ Follow-up sampling ( memento of the original from October 9, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. in the Bizerba guidelines for quality
- ↑ Reduced initial sampling in the guidelines for quality assurance of supplies in the automotive sector of Magnetbau Schramme (PDF; 224 kB)
- ↑ Double sampling as subsequent sampling ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. at Grohe
- ↑ Sampling in the construction dictionary ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ House and home - sampling
