Airport Collaborative Decision Making (A-CDM)

Airport Collaborative Decision Making (A-CDM)


Most airport-related operational improvement initiatives are oriented towards improving performance of an individual partner at an airport. Airport CDM (A-CDM) is about partners working together and making decisions based on more accurate and higher quality information, where every bit of information has the exact same meaning for every partner involved. More efficient use of resources, and improved event punctuality as well as predictability are the target results. Put simply "It ensures that the right partners get the right information at the right time".

European A-CDM was based on the American concept of Collaborative Decision Making that was introduced in January 1998 to cope with heavy capacity reductions due mainly to en route or airport bad weather conditions. Delays during ground delay programs were reduced by 15 percent during the experimental period. In early 2000, trials were conducted at several major European airports to study and develop a CDM concept for Europe. This led to the creation of the Airport CDM Task Force under the EATM Airport Throughput Division (APT) to guide the Airport Operations Team (AOT) in A-CDM issues and undertake specific work.

The result was The European A-CDM Manual which details the elements Airport CDM Information Sharing, the turn-round process (Milestones Approach), variable taxi times, pre-departure sequencing and adverse conditions. The A-CDM Manual has been used to successfully guide several major airports to implement A-CDM and many airports are in the process of implementation.

A-CDM Benefits

Implementation of A-CDM allows each A-CDM Partner to optimise their decisions in collaboration with other A-CDM Partners, knowing their preferences and constraints and the actual and predicted situation.

The decision making by the A-CDM Partners is facilitated by the sharing of accurate and timely information and by adapted procedures, mechanisms and tools. The main A-CDM Partners are:

  • The Airport Operator
  • Aircraft Operators
  • Ground Handlers
  • De-icing companies
  • The Air Navigation Service Provider (ATC)
  • The Network Manager
  • Support services (Police, Customs and Immigration etc)

A-CDM Elements

The A-CDM concept is divided in the following elements:

  • Airport CDM Information Sharing – defines the sharing of accurate and timely information between the Airport CDM Partners in order to achieve common situational awareness and to improve traffic predictability. It is the core A-CDM Element and the foundation for the other Airport CDM Elements.
  • CDM Turn-round Process – Milestones Approach – this describes the progress of a flight from the initial planning to the take off from a CDM-A by defining Milestones to enable close monitoring of significant events. The aim is to achieve a common situational awareness and to predict the forthcoming events for each flight. The CDM Turn-round Process combined with the A-CDM Information Sharing Element is the foundation for the other A-CDM elements.
  • Variable Taxi Time Calculation – this consists of calculating and distributing to the Airport CDM Partners accurate estimates of taxi-in and taxi-out times to improve the estimates of in-block and take off times. The complexity of the calculation may vary according to the needs and constraints at the A-CDM. The aim is to improve the traffic predictability.
  • Collaborative Management of Flight Updates – this consists of exchanging Flight Update Messages (FUM) and Departure Planning Information (DPI) messages between the Network Manager and a CDM-A to provide estimates for arriving flights to CDM Airports and improve the ATFM slot management process for departing flights. The aim is to improve the coordination between Air Traffic Flow and Capacity Management (ATFCM) and airport operations at a CDM-A.
  • Collaborative Pre-departure Sequence is the order that aircraft are planned to depart from their stands (push off blocks) taking into account partners’ preferences (note: It should not be confused with the pre-take off order where ATC organise aircraft at the holding point of a runway). The aim is to enhance flexibility, increase punctuality and improve slot-adherence, allowing the airport partners to express their preferences.
  • CDM in Adverse Conditions – this consists of a collaborative management of the capacity of a CDM-A during periods of a predicted or unpredicted reduction of capacity. The aim is to achieve a common situational awareness among the Airport CDM Partners, including better information for the passengers, in anticipation of a disruption and expeditious recovery after the disruption.
  • Advanced CDM – as yet undefined, this will enhance and extend common situational awareness and increase collaboration between airport partners by utilizing advanced technologies and linking with advanced tools, i.e. A-SMGCSAMAN / DMAN.

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