Good practice guide on uncertainty evaluation for digital twins

This good practice guide (GPG) was written as part of the European Partnership on Metrology (EPM) project “Trustworthy virtual experiments and digital twins” (22DIT01 ViDiT), which has received funding from the European Partnership on Metrology, co-financed from the European Union’s Horizon Europe Research and Innovation Programme and by the Participating States. It has been prepared under the leadership of Politecnico di Torino (POLITO), in close collaboration with Università degli Studi di Padova (UNIPD), Laboratoire national de métrologie et d'essais (LNE), Université Sorbonne-Paris-Nord (USPN), GEOMNIA, TEKNIKER, IDEKO, VTT, Fundación para el Fomento de la Innovación Industrial (FFII), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Tecnología Industrial (INTI), and TUBITAK. This GPG summarizes and outlines methods to carry out the uncertainty evaluation for the DTs with a description of their application to the four complex measurement use cases: nanoindentation (POLITO, UNIPD), 3D robotic measurement (IDEKO, TEKNIKER, VTT), rotary table for primary angular measurements (LNE), and electrical measurement (UPM, FFII, INTI), addressed in the project. All these DTs include dynamic effects (such as thermal drift or vibrations); hence the model has to be updated according to the sensor data. In addition to providing practical guidance on the implementation of these uncertainty evaluation methods, the GPG presents a comparative analysis of their performance across the different DTs. This comparative evaluation is intended to support both technical decision-making and future developments in the field. This guide is aimed at metrologists, scientists, and engineers who are familiar with the basic ideas of uncertainty evaluation. A reader who is familiar with the Guide to the Expression of Uncertainty in Measurement (GUM) and its supplements or who is familiar with the Monte Carlo sampling method for uncertainty evaluation will be able to understand, and hopefully benefit from, this guide.