A certification according to quality standards like ISO 9001 describes and rates a corporation based on its processes. Additionally a range of standards exists, that rates quality, condition or safety aspects of a product (object-related).

A certification according to ISO 9001 creates trust at the site of a (potential) customer and conveys the high demands, made to the own quality management system, in a credible way to the audience.

The regular inspection of a once issued certificate on one hand serves the quality assurance and on the other hand it allows for a continuous enhancement of the own quality management.

If a company has been certified, it agrees to validate and test its products—including the purchased components—accurately on their safety and functioning. To minimize the on-site testing efforts it is possible to access components that on their part have been produced in certified companies.

This way, suppliers are forced to run a comprehensive final inspection of their components and sub-assemblies. This can be done with visual inspections, mechanical tests but also with electrical tests (e.g. cable test, open test, short test, functional test, component test, high voltage test, insulation test). For retracing issues, the test results are often logged per unit under test (UUT) and stored in a database.

For certified companies, diagnostics of the switching matrix, generator and measurement units are often mandatory.