Validation projects

User-driven prioritisation process (UDPP) departure

Release: 2014

Reference: -

Location: Paris


Taking place during pre-tactical operations, this solution provides airspace users with an easy and user-friendly way to identify their best swapping partners, as well as accrued flexibility in the slot-swapping rules such as multi-swap and substitution on cancellation. The slot-swapping tool allows airspace users to gain efficiency in the process of querying and identifying a partner for a slot-improvement, delay, or substitution on flight cancellation.

Validation results

As part of the SESAR DFlex demonstration project and using a pre-departure sequencing process currently in operation at Paris Charles de Gaulle Airport, exercises validated flight re-ordering based on airline business requirements.

The results were as follows:

• Increased flexibility for airspace users to re-order their flights in the pre-departure sequence;

• Maintained levels of safety, air traffic control operations, airport capacity and overall traffic punctuality;

• Increased decision-making and re-ordering activities by flight operations centre staff.


The validation results for this solution are conclusive and sufficient to support a decision for industrialisation. This locally-deployed solution relies on having A-CDM in operation, and a pre-departure sequencing strategy to assign TSATs well in advance based on the “first-scheduled-first-served” principle. Adaptations would be needed in order to deploy this  solution at airports with alternative pre-departure sequencing policies.