Efficiency plays a central role in evaluating the capability of the Electric Drive Module (EDM) to convert electric energy into mechanical energy. This master’s thesis focuses on optimising the testing methodology used to measure the EDM efficiency, defining the accuracy and repeatability levels of the tests. The accuracy of the EDM efficiency measurements is strongly dependent on the testing methodology, as factors such as measurement instruments precision, calibration, data acquisition rate and environmental conditions can all introduce uncertainty. Measurement quality is characterised by accuracy and repeatability, which can be assessed through uncertainty evaluation. Accuracy refers to the closeness of a measurement to the true value, whereas repeatability describes the consistency of a measurement under identical testing conditions.