As described in a comprehensive review (1), the core component of standardization is the “establishment of metrological traceability”. In practice, the standardization process requires the availability of an ISO conform reference measurement system (2). This comprises the definition of the measurand and units for expression of measurement results (ideally the Système International d’Unités or SI), as well as different hierarchical levels of materials and measurement procedures. The reference measurement system is intended for use as calibration hierarchy. As a result, the calibrated hierarchically lower measurement procedures – IVD assays used in routine laboratories – will provide measurements traceable to the top of the hierarchy – the unit and its realization in the primary calibrator – within stated uncertainty constraints. Figure 1 shows the structure of an ISO conform reference measurement system.