The German Incentive Regulation Ordinance (ARegV) provides for the use of quality elements in the regulation of energy supply networks. The application of quality elements is intended to ensure the long-term, efficient and reliable operation of energy supply networks. The main dimensions of supply quality are grid reliability and grid efficiency. This study examines the quality element on the basis of network reliability and its integration into the revenue cap of electricity distribution service operators. It is shown how an effective development of the existing quality regulation is to be designed or whether the existing regulation concept is to be confirmed.