In vitro diagnostic devices (IVD) are categorized into different risk classes depending on the potential consequences of false test results in transfusion medicine or on the individual patient. Test systems of higher risk may be assessed and examined by a third party in addition to the manufacturer's evaluation. The preapproval examination of essential performance features can assure minimum quality features prior to marketing of the IVDs. By batch testing the variation between different batches of an IVD is determined. Comparative testing in a re-evaluation scheme can define the current state of the art. The present European IVD directive stipulates batch testing for high-risk IVDs while the draft version of the new European IVD regulation also foresees independent product testing performed by European reference laboratories.