Article 25 — Performance monitoring

1. The national supervisory authority shall assess, in cooperation with the national competent authority without prejudice to the national arrangements resulting from Article 4(5), whether the air navigation services provided in the airspace under their responsibility meet the performance targets contained in the performance plans approved in accordance with Article 24 and whether those plans have been implemented correctly, and shall implement the incentives schemes referred to in Article 21(4), point (i). 2. The national supervisory authority shall issue regular reports on the monitoring of performance of air navigation services provided by the air navigation service providers designated under Articles 8 and 10 and make them available to the Commission. The results of those assessments shall be made publicly available without prejudice to Article 52(3). The air navigation service providers designated under Articles 8 and 10 shall provide the information and data necessary for such monitoring to the national supervisory authority. This shall include information and data related to actual costs of the services provided and procured and related revenues. 3. To the extent that the air navigation service provider has reasonable means to mitigate the impact of external factors, where performance targets contained in the performance plans are not reached or the performance plan is not correctly implemented, the national supervisory authority shall require corrective measures to be implemented by the air navigation service providers concerned. Those corrective measures shall be adequate to improve the performance and proportionate, in particular considering interdependencies with safety and between performance areas, and the impact on the network. Where corrective measures imposed are not properly applied, the Member State concerned shall take appropriate measures and inform the Commission. In the event of persisting underperformance, the Commission may take action in accordance with Article 34(2) and 34(3). 4. The Commission shall monitor the performance of the provision of air navigation services and network functions on the basis of the reports of national supervisory authorities and of analysis of data received and shall carry out regular assessments of the overall achievement of the Union-wide performance targets and present the results to the committee referred to in Article 48(1).