# Airport Collaborative Decision Making A-CDM is a coordination framework, not a technology. It exists because airports have a structural problem: multiple independent stakeholders (airport operator, airlines, ground handlers, ATC, network manager) each making decisions based on incomplete information about what everyone else is doing. The core mechanism: 16 milestones tracking an aircraft from approach through turnaround to takeoff. Each milestone triggers information sharing between partners, updating downstream estimates. Key timestamps include TOBT (Target Off-Block Time), TSAT (Target Start-up Approval Time), TTOT (Target Take-Off Time), and CTOT (Calculated Take-Off Time). When all partners share accurate, timely updates on these milestones, the system gains predictability. Results from European implementations: 0.25 to 3 minutes saved in average taxi-out time per departure, dramatically improved take-off time predictability, reduced ATFM slot wastage. These sound small. Multiply by hundreds of daily departures and you get real money. A-CDM is fully implemented at 34 European airports including Heathrow, Frankfurt, Amsterdam, CDG, and Munich. The US equivalent runs through the FAA's CDM program and tools like Terminal Flight Data Manager (TFDM). Implementation takes years because it requires all stakeholders to change workflows and trust shared data. The technical integration is the easy part. The organizational change management is where implementations stall. The evolution: A-CDM connects one airport's operations. [[Total Airport Management]] extends the scope to include terminal and landside operations. Network-CDM would optimize across multiple airports simultaneously. Each step requires deeper integration and more trust between parties that have historically optimized independently. Related: [[Aircraft Turnaround]], [[Airport Operational Database]], [[Airport Operations MOC]], [[Total Airport Management]] --- Tags: #deeptech #firstprinciple