According to ISO 17043, an interlaboratory comparison (ILC) is the organisation, performance and evaluation of measurements or tests on the same or similar objects by two or more laboratories or test centres under specified conditions.

Differentiation: Proficiency testing vs. EQA-Scheme vs. interlaboratory comparison

While the terms are often used interchangeably, there are important differences:

Proficiency testing:

– Organised and managed by an independent third party

– Includes the participation of a laboratory

– Uses its results to determine the performance of the participants

– Is a formal audit with a standardised report

– Represents objective evaluation criteria

Interlaboratory comparison (ILC):

– Carried out by mutual agreement between participating laboratories

– Can be carried out without an independent provider

– Used for comparison between laboratories, but not necessarily for formal accreditation

EQA-Scheme:

– German technical term for aptitude test

– Includes all elements of a formal proficiency test according to ISO 17043