The on-site assessment is sometimes referred to as an audit. The purpose of the examination is to determine by observation whether the work of the laboratory is carried out in compliance with the documented quality system. The examination also reviews compliance with the CCKL Code of Practice, specific professional criteria and the principle of 'state of the art'.

The independent examination team from CCKL mainly looks at the functioning of the entire organisation, and the performance of laboratory tests.

The first part is mainly the task of the team leader. He conducts interviews with management in order to gain an impression of the quality system in practice, and employee commitment to the quality system.
The second part is mainly carried out by experts in the specific field. They look into a number of processes in depth. And comprehensively review such aspects as thoroughness, safety, calibration, traceability, results of quality control programmes, presence of good instructions, correct diagnoses and results, good judgment and reporting.

The examination team prepares a report on its findings. Besides the narrative text, it contains an summary table This shows at a glance how the laboratory has scored on various aspects. The table makes a distinction between documentation and implementation. This is necessary because the implementation may be better than the documentation, but the reverse can also be the case. In fact, this table gives a summary of the findings of the assessment team, and it determines just how accreditation-worthy the institution is.