Analysis of the relationships between proficiency testing, validation of methods and estimation of measurement uncertainty: a qualitative study with experts

Proficiency testing (PT) is an important part in the process ensuring quality of results. Validation of methods and estimation of measurement uncertainty are also vital elements in a laboratory qualification process. The main objective of this paper is to identify the relationships between PT, validation of methods and calculation of measurement uncertainty through the drawing up of a Mind Map. The method proposed used the Web-based Delphi method to conduct a qualitative research with experts of the area (laboratory assessors and accreditation body members). Experts from five accreditation bodies (Brazil, USA, France, Portugal and China) took part in the research. The study led to the drawing up of a Mind Map showing the connections of cause and effect between the factors under study. It emerged that PT effectively contributes to the reliability of results, since it is directly related to the validation of methods and to measurement uncertainty, so as to increase laboratory’s competitiveness.