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Initial sample inspection report

Measurement News from Q-Tech

What is an initial sample inspection report (EMPB)?

To reduce time and costs, it is important to identify and avoid any production errors at an early stage. For this reason, products are not produced in large quantities until series production has been tested and sampled under realistic conditions. If these initial samples meet the quality requirements, production is released. This process guarantees that companies do not produce goods or products until they meet the required quality standards. This quality inspection is known as initial sample inspection, the results of which are recorded in the initial sample inspection report.

But what is the initial sample test report (EMPB)? The initial sample test report (EMPB) is an important part of the initial sample test. It documents the results of the sampling process for an "initial sample". 

The initial sample inspection report not only plays an important role within the company. It is also of immense importance in the B2B area. For example, a supplier can prove that the delivered products meet the customer's quality requirements. 

Why is an initial sample inspection report necessary? 

An initial sample inspection report is carried out either according to a customer's specifications or according to a company's own quality requirements. The purpose is to check whether a product is suitable for series production and can be produced in consistent, constant quality. In order to find answers to these questions, a fixed number of units of the respective products are examined and the results are documented in the initial sample test report. The aim is to reduce and prevent defects even before series production. In addition, in the B2B sector, customers and suppliers can use an initial sample inspection report to reach basic agreements. The test reports often differ significantly in their complexity and scope. Furthermore, an initial sample inspection report is also binding. This means that if the tested product is produced again, it must correspond to the initial sample, provided that no defects have been detected. This also means that all newly produced goods must be manufactured under the same conditions as the initial sample. This is the only way to guarantee consistent quality. This is because even the smallest changes can cause a production run to be different than planned. The reasons for this can be manifold:

  • Incorrect settings in the production machines.
  • Incorrectly designed production parameters.
  • Defects in the means of production.
  • Errors in the measuring equipment.
  • Error in the specification of the source material.
  • Environmental factors not taken into account.
  • Influences due to on-site conditions not taken into account.

Example scenario, explaining the need for initial sampling:

If a product is ready for series production, a test series is carried out for initial sampling before actual production. During this process, it is noticed that the tested initial samples deviate from the dimensional specifications and the desired quality. When investigating the cause, it is recognized that, for example, the clamping force of the tools was not high enough or that the air was too dry and thus the processed material experienced a negative change. Only with the initial sample inspection report, however, is it then possible for the manufacturing companies to carry out an exact ACTUAL analysis and eliminate the causes or errors. 

What is the reason for an initial sample inspection?

The reasons for an initial sample inspection can be many and varied. Among others:

  • The cooperation with a new supplier/subcontractor of materials
  • A new production part
  • Changed product specifications
  • New or modified tools
  • New or modified manufacturing processes
  • New production facilities
  • A production interruption

What are the economic reasons for an initial sample inspection report

The initial sample inspection report is intended to determine whether the projected series production is actually economically viable. Therefore, the initial sample inspection report establishes a comparison between the target data of a produced item and the average properties from the pre-series production.

Only when the planned manufacturing process appears viable and correct in reality is continuous production with consistent quality and increasing profitability likely.

Is the initial sample inspection report subject to certain standards and specifications?

By the way, the initial sample inspection report is not a "German invention". In general, it is common practice in industry. It is laid down in the VDA, Volume 2 - Assuring the Quality of Deliveries. In general, Volume 2 of the VDA describes the procedures for production process and product release. This is a core element for customer-specific requirements. 

Other applicable standards, in connection with the sampling of an initial sample and the preparation of a test report are: 

  • All requirements of QS 9001 or VDA series as well as ISO TS 16949 (valid version).
  • Relevant DIN ISO standards.
  • Terms and conditions of purchase of production materials, spare parts and direct means of production of the products.

Where does initial sampling come into play?

Especially in the automotive industry, initial sampling is standard. Unified guidelines such as IATF 16949 and PPF/PPAP ensure a standardized process for product sampling in the automotive industry and close cooperation between the customer and the supplier. However, initial sampling is also the order of the day in all other manufacturing companies. Especially when new products are to be launched on the market. 

Scope of an initial sample inspection report

In order to be able to make valid statements regarding a new product, it is not sufficient to sample the first product produced in a series production. Only after a statistically reliable quantity has been tested is it possible to make a qualified statement about the usability of the production and the production conditions. In this context, the quantity of tested products for the initial sample test report is based on the empirical values that could already be made in connection with the production equipment. This includes, among other things, the wear limits of the processing machines. For example, tolerance deviations of the cavities in injection molds, casting molds, compression molds and die-sinking molds are quite normal after a corresponding number of cycles. Just as carbide cutters and inserts wear at different rates when machining material of different hardness or softness.

Scope of testing during initial sampling

The scope of the initial sample inspection depends on the specifications and tolerances. Usually, however, the initial sample inspection checks the optical, metric and technical properties of a manufactured product.

  • Optical properties include burrs, porous material, roughness, dents, scratches, opacities.
  • The metric properties are sometimes the most important points of the initial sample inspection. Here, all dimensions and weights are checked. For this purpose, the products are checked manually, by tactile or optical measurement. Measurements with a computer tomograph are also possible here.
  • When testing the technical properties, the load-bearing capacity of a product is examined. Tensile, breakage and bending tests can be carried out for this purpose. As soon as non-destructive tests are required, X-ray and ultrasonic tests are used. Another part of the technical testing is the examination of the material composition of the starting material. This is accomplished by means of a spectrometer.

In general, the scope of testing is always tailored to the respective product. The respective manufacturers and the testing service providers agree this with each other in advance.

What happens if the initial sample inspection report is negative?

Ideally, the initial sample already meets all quality requirements. However, this is wishful thinking. As a rule, an initial sample is repeated until all quality requirements are met. In the process, each adjustment interval requires a new initial sample test report when test production is restarted. In this report, all changes, be they improvements or deteriorations, must be precisely documented in order to be able to trace them accordingly. For this reason, the initial sample test report is also valid in the event of legal issues. In this context, the initial sample inspection report is also subject to a statutory retention period. This is based on Section 257 (1) HGB and Section 147 AO and is 10 years.

What does a complete initial sample inspection report contain?
A complete initial sample inspection report includes a cover sheet with all data, the actual measurement report with all dimensions and at least one stamped drawing. It may also include an inspection certificate for raw material. Furthermore, a complete initial sample inspection report includes:

  • Dimension, material, function test report
  • Sample parts (5 pieces, for multiple tools 5 pieces per nest)
  • Additional documents (e.g. process flow chart, production control plan)
  • Process capability proofs, measuring equipment capability proofs
  • Material certificates (material certificate, safety data sheets, if applicable)
  • All material data and IMDS identification number information on the cover sheet.

Depending on the order, either the forms of the valid VDA Volume 2 or the valid AIAG PPAP (Production Part Approval Process) must be used.

Deviations from the permissible tolerances must be noted in the test report. Here, the required accuracy depends on the respective application and/or the specification of the parts. With regard to tolerances, the following applies: the measuring and test equipment uncertainty should not be higher than a maximum of 10% of the smallest permissible tolerance of the measuring and test criteria. For example, if the smallest permissible tolerance may only be ±0.3 mm, the minimum accuracy of the measuring and test equipment is 0.06 mm.

Information on the cover sheet of the initial sample inspection report

  • Part name and part number
  • Any safety parts must be noted.
  • The index of the component must be noted.
  • The weight in kilograms.
  • The current ID number
  • Reason for submission and the required submission level

The actual measurement report

In the actual measurement report, the number of samples to be measured is noted. According to VDA, this is 5 samples, for example. In the case of a successful inspection, all items must be assessed as OK. In general, all parts must be measured separately for an initial sample inspection report. All position tolerances must be documented as position tolerances. 

The material report

The materials report contains, among other things, notes and information on: 

  • Geometry, dimensional inspection
  • Function test
  • Materials testing
  • Haptics test
  • Acoustic test
  • Odor test
  • Appearance check
  • Surface inspection
  • ESD - Testing
  • Reliability check
  • Release of coating systems
  • Other

Stamped drawings

Product-related, stamped drawings are also part of an initial sample inspection report. Here, all product features, such as dimensions up to standards or specifications, as well as written product requirements such as the pore definition, surface definition, marking of the casting, etc. must be stamped. The stamping serves as numbering and at the same time allows a clear assignment of the results.
All features are to be clearly identified on the drawing by consecutively numbered item numbers.

What is the difference between an initial sample inspection including initial sample inspection report and a follow-up sample inspection?

A follow-up sampling is a repeated sampling of a product after the resumption of a production. This can be the case, for example, after a production interruption of several months. Follow-up sampling is sometimes also referred to as reduced initial sampling. However, this is not factually correct, as a follow-up sampling is never an initial sampling. 

In general, the initial sample inspection report is an important factor for error-free and efficient production in industry and business. The focus is primarily on consistent quality in series production, which can be verified with an initial sample inspection report.