Proficiency testing, as a quality assurance tool, allows the laboratory to compare its performance with others, detect trends and therefore, take any preventive or corrective action that is necessary to ensure technical competence and continuous improvement. In this sense, the criteria defined by ONAC for the participation of the laboratories in Proficiency Testing according to (CEA-3.0-04 version 03) "Policy for the participation in Proficiency Testing (PT) in Laboratories", have the purpose of using the performance results obtained by the laboratory, to evaluate the technical competence in the application of specific testing methods.
Taking into account the above and the requirement of the NTC ISO IEC 17025:2017 number 7.7.2, the laboratory shall monitor its performance by comparison with the results of other laboratories, where available and appropriate. This monitoring should be planned, reviewed and should include participation in proficiency testing.