Proficiency Testing is the use of inter-laboratory comparison for determining the performance of individual laboratories for specific tests. Participation in proficiency testing programmes provides laboratories with an objective means of assessing and demonstrating the reliability of data they are producing. The primary objective of proficiency testing is to provide the laboratories with an information and support to demonstrate and improve the quality of their analytical measurement. It also supplements the laboratories own internal quality control procedures by adding an additional external evaluation of their testing capabilities. However, to produce the authenticated test data, it is required to maintain quality management system in that laboratory. ISO/IEC 17025 has prescribed the requirements for maintenance of quality system in the testing and calibration laboratories. Testing and Calibration Laboratories use this standard in the development and implementation of their Quality System. Accreditation bodies use this standard to assess the testing / calibration laboratories for considering of accreditation.

To meet the requirements of APLAC MR001 it is mandatory for all accrediting bodies to undertake proficiency testing programmes for its accredited laboratories. All applicant laboratories are required to successfully participate in at least one Inter - Laboratory Proficiency Testing in accordance with ISO / IEC 17043.

For calibration laboratories, measurement audits will be considered to be a complimentary effort to Inter-Laboratory Proficiency Testing. Technical assessors for calibration laboratories will be provided with artifacts with their characterization by National Physical Laboratory, New Delhi or any other NMI's who are signatory to BIPM including PTB and NIST. NABL regularly organizes PT programmes for its accredited as well as applicant laboratories. Non-accredited laboratories are also invited to participate in these programmes. The programmes are run through nodal laboratories identified by NABL. NABL has also prepared & published NABL - 162 Guidelines for Proficiency Testing programmes for Testing and Calibration Laboratories for conducting PT programmes NABL regularly participates in the PT programmes organized by APLAC and other international bodies.

Proficiency Testing Programmes by other agencies

NABL encourages participation of applicant / accredited laboratories in Proficiency Testing programs conducted by other national & international bodies. Accredited laboratories are encouraged to participate in as many of these external programs as possible to enhance their quality assurance. This list is by no means exhaustive and contains links to national and international programs for which information was available.

The links in this list does not imply its formal endorsement by NABL.

• American Association for Laboratory Accreditation (A2LA)
• AOAC International
• Asia Pacific Laboratory Accreditation Cooperation (APLAC)
• ASTM International
• Centers for Disease Control and Prevention (CDC)
• China NIL Research Center for Proficiency Testing
• CSL Proficiency Testing Group
• European Information System on Proficiency Testing Schemes (EPTIS)
• Laboratory of Government Chemists (LGC)
• National Association for Proficiency Testing (NAPT)
• National Association of Testing Authorities (NATA), Australia
• National Institute of Standards and Technology (NIST)
• United Kingdom Accreditation Service (UKAS)
• College of American Pathologists (CAP)
• All India Institute of Medical Sciences-Hematology (AIIMS)
• RANDOX Clinical Diagnostics Solutions
• BIO-RAD