It´s part of human nature to avoid less comfortable aspects of reality and focus on its most glamorous details.

That explains why, in 2012, when ICAO published its Manual on Collaborative Air Traffic Flow Management (Doc. 9971), air transport planners, in numerous regions, opted for ignoring a number of ICAO cautious reminders:

• "The overall objective of the process is to improve the performance of the ATM system as a whole while balancing the needs of individual ATM community members."
• "The expectations of the members of the ATM community would be balanced to achieve the best outcome based on equity and access."
• "CDM is a process applied to support other activities such as demand/capacity balancing. Although information-sharing is an important enabler for CDM, sharing of information is not sufficient to realize its objectives"

It should be obvious, for any unbiased reader, that CDM Operations concept seeks to balance Demand vs Capacity by ensuring equity of access to finite resources (airspace and airports´ surface) by multiple ATM community members (Aircraft Operators).

Under such perspective, information sharing is the best option for aircraft operators, to communicate their flight intentions, with a view to ensure necessary sacrifices, for Demand x Capacity balance, may be evenly distributed, under CDM´s "equity of access" spirit.

That, however, would require ATM community members to understand CDM Operations concept proposes evenly distributed sacrifices, whenever Demand exceeds Capacity, as a means to avoid fuel waste and unnecessary CO2 emissions, associated with long takeoff cues and unproductive airborne holdings.

A decade was gone and human nature is still preventing air transport planners, in many regions, to look at CDM Operations´ Pains and Gains, under a realistic perspective.

Telling people that "capacity might be increased by simply sharing information", is for sure a way more glamorous promise, but no lie lasts forever and that´s what many aircraft operators learned, the hard way, the first time they were assigned a CTOT or a TSAT -5/+5 min !

So far, CDM Operation has been treated as a delusional promise - "Collaborate and share information" for magic capacity increase !

Sooner or later, however, air transport planners will need to realistically understand and consider "the pains and gains" of what "CDM option" actually proposes to airlines, when Demand exceeds Capacity:

Share absolutely accurate estimates (Targets) of their flight readiness times and Collaboratively accept delays, arising from conflicting interests (CTOT, TSAT>TOBT) or poor accuracy of their "Targets" (expired TSATs).

CDM Operation is certainly a consistent way forward, for those committed to avoid unnecessarily costly and environmentally damaging operation, but it´s imperative to understand, accept and communicate CDM´s Pains and Gains !