Use the uncertainty in conformity assessments because it is…honest!

The new requirement of the ISO/IEC 17025 standard for discussing with the customers the impact of the measurement uncertainty in the reliability of conformity decisions and for subsequently using it in conformity assessments is not just another novelty of the standard. It represents a very important evolution of laboratory accreditation that will generalise the quantification of how good decisions supported on measurements are.

The only difficulty for implementing this transparent way of managing conformity assessments is the complexity of the involved statistics. This requirement is a new challenge for laboratories, but a very important one for the end-users of conformity assessments…all of us!

ForMEQ, the “International Forum on Metrology and Examinology in Chemistry” ( developed an MS-Excel spreadsheet, available in English and Portuguese, that makes the use of measurement uncertainty in conformity assessments very easy. It is applicable to cases where the measurement results have a normal distribution and the conformity decision is supported on the comparison of the measured value of a parameter with a limit or tolerance interval.

Let’s move forward and help laboratories in doing their job in the best way!

Links to the ForMEQ spreadsheet on automatizing and simplifying the use of the measurement uncertainty in conformity assessments:

English version – Instructions:

English version – Spreadsheet:

English version – Explaining video:

Portuguese version – Instructions:

Portuguese version – Spreadsheet:

Portuguese version – Explaining video: