Effective quality assurance only works if checks are carried out in a transparent and independent manner. The QS scheme therefore deliberately relies on three levels of control: firstly, the businesses themselves check whether all requirements have been met and properly documented – supported by QS with clear guidelines, manuals and practical tools. This is followed by independent checks carried out by qualified auditors, as well as participation in comprehensive monitoring programmes that, amongst other things, identify anomalies at an early stage. Finally, QS ensures that auditors, laboratories and certification bodies also operate reliably by monitoring their own work. Taken together, this ensures that quality assurance really works: transparently, robustly and in a way that is traceable for everyon