The objective of the DFLEX project was to demonstrate enhanced flexibility to the Pre-Departure Sequencing process currently in operation at Charles De Gaulle Airport, by allowing flight reordering based on airline’s business requirements. Reducing the airline cost of the airside delay was aimed as output.

Number and duration of trials
• More than 2000 flights were involved.

All trials are be executed in CDG in different seasons.
• The main flexibility function “Reordering (flight sequence reordering) - TSAT update according to the airline request” was tested, allowing airlines to swap the priority of 2 flights, with more than 50 flight involvement.
• Based on the success of the first trials, it was decided to keep the functions open allowing at demonstrating the DFlex benefits in disrupted situations encountered during the summer 2013. By November 2013, more than 500 flights had been involved.
• During the second phase from December 2013 to March 2014, 2 other features were tested: (“ready to depart” reordering (the prioritization of a flight among all the other flights of the airline) and the substitution (ownership of departure order  after cancellation - use of a departure slot belonging to a flight that the airline had previously cancelled). 1500 additional flights were involved in this second phase only.
The following table shows the impact on TSAT for flights associated to a DFlex action and the impacted flights. The flight associated to a DFlex action got a significant improvement. And it is interested to notice that the other flights (so-called the “impacted flights”) were not penalized.