It is a method used to evaluate the efficiency and the validity of results, and to verify laboratory performance by comparing the results with reference results for specific tests or measurements.

In addition, international standards, such as (ISO\IEC 17025) require the accreditation bodies to consider the laboratories' participation and their performance levels in the proficiency test as an objective tool to confirm the eligibility of the entity to obtain accreditation;   this explains the increasing need for proficiency tests.

The need for continuous trust in laboratories' performance is not only essential for laboratories and their customers, but also to stakeholders such as regulatory bodies, laboratories accreditation bodies, and other organizations that define laboratories requirements. Participation in technical proficiency test has the most important benefits, which are:

• Assessing laboratory performance for specific tests or measuring and monitoring continuous laboratory performance.
  
• Identification of laboratories' problems and propose improvement procedures.
• Provide additional trust to laboratory customers.
• Determine the reasons of differences between laboratory results.
• Improving the performance of participating laboratories based on the results of the comparisons.
• Verify uncertainty accounts.
• Determine the value of reference materials and assessing their suitability for use in specific testing of measurement procedures.