(17)Finally, account should be taken of the capacity enhancement measures of ANSPs which have already been included in the European Network Operations Plan (‘NOP’) referred to in Article 9 of Implementing Regulation (EU) 2019/123. The latest available edition of the NOP, covering the time period 2023-2027note, includes capacity improvements by most ACCs which have been historically significant contributors to en route ATFM delays, including the implementation of state-of-the-art ATM systems and advanced ATC tools. Based on the available analysis, those investments will significantly enhance the capacity performance in those ACCs in the course of RP4. Specific operational benefits are also expected in RP4 from the ATM functionalities part of the SESAR ‘Common Project One’ and laid down in Commission Implementing Regulation (EU) 2021/116note, which will be deployed during the RP4 timeframe.