1. www.metsci.com/cdm

2. Vastly Distributed System ATCSCC CDM net TFM hub TRACONs TRACON(s) Towers ARTCC ARTCC(s) Towers Airports Industry AOC(s) GA International Military Capacity/Demand Forecasts ? ? ?

3. CDM History

4. Schedule Delay Delay Crews FAs Airframe Passengers

6. Non-linear Response to Capacity Reduction Reducing the airport capacity to 50%, generates over 65,000 minutes of delay at the airport and 139,000 minutes system wide.

7. Goals of CDM Transfer business decisions to users Use available capacity efficiently Improve predictability Ensure that the system is fair

9. The Pillars of CDM Analytical Capability Distributed Planning Common Situational Awareness Measurement What-ifs Efficiency Equity Dynamic Decision Points Infrastructure Message Formats Display Tools

10. The most profound impact on the ability of Airline Operational Control Centers to interface with Traffic Flow Management has been the advent of the Aircraft Situational Display.

12. What is a Ground Delay Program? A ground delay program (GDP) is implemented at an airport when arrival demand exceeds capacity Demand is under capacity => no problem Capacity has dropped below demand => problem for 4 hours

13. Ground Delay Program Goal Balance capacity and demand at impacted airport. l Delays taken on the ground, not enroute l Reduces airborne congestion l Delivers smooth and reduced arrival rate to the airport

14. Determine a set of feasible arrival slot times {s i } where T 1 = the start time of the program and AAR t = the arrival acceptance rate at time t Assign flights to arrival slots Fundamentals of a GDP: Adjust Demand to Meet Capacity

15. Each flight i has a reported arrival time t i Let x i,j = 1 if flight i assigned to slot j, 0 otherwise Solve to minimize total delay Initial Approach to Assigning Arrival Slots: Ration by Reported Demand subject to Original schedule Arrival slots

16. External circumstances can change an airlines schedule Problems with Rationing by Reported Demand Arrival slots Original schedule

17. Modified schedule External circumstances can change an airlines schedule Flights are cancelled Flights are delayed Reporting these changes can help competitors more than the reporting airline Problems with Rationing by Reported Demand Arrival slots delay cancellation

18. Original System Could Not Respond to Airline Actions Airlines operate flights in banks to facilitate passenger connections Ground Delay Programs disrupt banks Arrival slots Original schedule

19. Airlines operate flights in banks to facilitate passenger connections Ground Delay Programs disrupt banks Airlines respond by delaying flights to preserve banks => demand and capacity again out of line ATM control only dictates earliest time a flight can arrive Arrival slots Original schedule Original System Could Not Respond to Airline Actions

20. Flights are assigned to arrival slots based on known demand Unexpected flights appear (military, general aviation, others unscheduled) Demand again exceeds capacity leading to airborne holding, diversions and ground stops Arrival slots Original demand Original System Could Not Respond to Airline Actions Revised demand

21. CDM Approach to the Problem Recognize that this is best addressed as a distributed optimization problem –FAA allocates arrival slots to airlines equitably and efficiently –airlines assign flights to their allocated arrival slots optimize their own cost function –iterative approach continual re-evaluation of demand vs. capacity and adjustments as necessary Allocation of slots must be equitable, and reward rather than punish data exchange Assigns flights to slots and adjusts demand based on economic objectives FAAAirlines Assigns slots based on capacity

22. Equitable Allocation of Arrival Slots: Ration by Schedule Original schedule Arrival slots Arrival slots are distributed according to published schedule rather than reported demand

23. Equitable Allocation of Arrival Slots: Ration by Schedule Original schedule Arrival slots Arrival slots are distributed according to published schedule rather than reported demand When flights are cancelled or delayed, airlines retain rights to those slots Cancelled slot still owned by blue airline cancellation delay Modified schedule

24. Arrival slots are distributed according to published schedule rather than reported demand When flights are cancelled or delayed, airlines retain rights to those slots Airlines can assign flights to slots in whatever way best suits their business needs An optimal solution is found that is accepted and understood Equitable Allocation of Arrival Slots: Ration by Schedule cancellation delay Cancelled slot still owned by blue airline Modified schedule Arrival slots

25. Often airlines are unable to use their allocated slots Without FAA action, resources would be wasted Compression, moving flights up to fill vacant slots, benefits everyone Maximizing Available Resources: Compression Modified schedule Arrival slots

26. Often airlines are unable to use their allocated slots Without FAA action, resources would be wasted Compression, moving flights up to fill vacant slots, benefits everyone Maximizing Available Resources: Compression Modified schedule Arrival slots

27. Original demand Original program Program Revisions Adjust to Changing Conditions Original program based on known demand

28. Program Revisions Adjust to Changing Conditions Original program based on known demand When demand changes existing program becomes invalid Expected arrivals after revision Revised demand

29. Program Revisions Adjust to Changing Conditions Original schedule Expected arrivals after revision Revised demand Original program based on known demand When demand changes existing program becomes invalid Revision of the program reassigns arrival slots to updated demand Balance between demand and capacity is restored Delays are taken on the ground rather than in the air. This is cheaper for the airlines and safer for the flying public.

30. Pre-CDM GDP Process No opportunity for the airlines to solve the problem and avoid the GDP No ability for the FAA to respond to changing conditions with revisions or compressions No smooth transition out of the GDP FAA/Airline Evaluation Demand Vs. Capacity GDP Modeling Send GDP Advisory Issue GDP (Ration by reported demand) Airline Response (Substitutions & Cancellations) Program expires or is cancelled

31. Current CDM GDP Process FAA/Airline Evaluation Demand Vs. Capacity GDP Modeling Send Proposed GDP Advisory Airline Response (cancellations) Is GDP still required? Issue GDP Airline Response (Substitutions & Cancellations) Compression GDP Revision /Extension Yes End No Exit loop when program expires or is cancelled. (Ration by schedule)

32. Collaborative Decision Making Capacity/Demand Management

33. Passengers 60 116 93 87 Total 443 P-DELAY = #PSGR X min DLYD P-Delay min = 26580 P-Delay min =3600 Original P-Delay is 738% greater than revised Passengers 0 CNX 176 (60 late) 93 87

34. Some Perceived Problems Airlines are over-scheduling airports Airlines are withholding delay and cancellation information from the passengers.

35. Over-scheduling? PHX schedules at VFR conditions for certain time frames. –344 days without a GDP from June 2000 to present. –GDP delays range from 60 to 238 minutes –6,192 more scheduled operations, than if scheduled to IFR conditions.

36. Over-scheduling? BOS schedules at VFR conditions for certain time frames. –250 days without a GDP from June 2000 to present. –GDP delays range from 50 to 130 minutes –12,250 more scheduled operations, than if scheduled to IFR conditions.

37. TFM Dependencies Although, the capacity at an airport is reduced and ATC delay has been applied, users may cancel and delay flights as well as notify the FAA of earliest feasible departure times of flights. FAA Actions Cancellations Airline Delays beyond ATC delay Earliest Departure/Arrival Time updates Airline Actions Issue ATC delay Generate Demand

38. Collaboration is Essential to Maximizing Resources When Capacity is Reduced, Airlines Adjust their Schedules by Delaying, Canceling and Substituting Flights. These Schedule Changes are Communicated to the FAA through the CDM Network. The FAA Uses this Information to Maximize Capacity Usage through Revisions, Compressions, and other Delay Reducing Procedures. To Achieve this Efficiency, Departure Times Must Remain Flexible. Delays that are Communicated to the Passengers are difficult to Reduce.

39. Airline and FAA Actions can Reduce Delays

40. Future Steps for CDM Improve Demand-Capacity predictions –Demand Uncertainty –Capacity Uncertainty Improve dynamic resource allocation –User system dependencies –Passenger dependencies Integrated System Solutions –Local versus National Traffic Management Initiatives –Strategic versus Tactical Traffic Management Initiatives

41. CDM Approach to the Problem Recognize that this is best addressed as a distributed optimization problem –FAA allocates arrival slots to airlines equitably and efficiently –airlines assign flights to their allocated arrival slots optimize their own cost function –iterative approach continual re-evaluation of demand vs. capacity and adjustments as necessary Allocation of slots must be equitable, and reward rather than punish data exchange Assigns flights to slots and adjusts demand based on economic objectives FAAAirlines Assigns slots based on capacity

42. Equitable Allocation of Arrival Slots: Ration by Schedule Original schedule Arrival slots Arrival slots are distributed according to published schedule rather than reported demand

43. Equitable Allocation of Arrival Slots: Ration by Schedule Original schedule Arrival slots Arrival slots are distributed according to published schedule rather than reported demand When flights are cancelled or delayed, airlines retain rights to those slots Cancelled slot still owned by blue airline cancellation delay Modified schedule

44. Arrival slots are distributed according to published schedule rather than reported demand When flights are cancelled or delayed, airlines retain rights to those slots Airlines can assign flights to slots in whatever way best suits their business needs An optimal solution is found that is accepted and understood Equitable Allocation of Arrival Slots: Ration by Schedule cancellation delay Cancelled slot still owned by blue airline Modified schedule Arrival slots

45. Often airlines are unable to use their allocated slots Without FAA action, resources would be wasted Compression, moving flights up to fill vacant slots, benefits everyone Maximizing Available Resources: Compression Modified schedule Arrival slots

46. Often airlines are unable to use their allocated slots Without FAA action, resources would be wasted Compression, moving flights up to fill vacant slots, benefits everyone Maximizing Available Resources: Compression Modified schedule Arrival slots

47. Original demand Original program Program Revisions Adjust to Changing Conditions Original program based on known demand

48. Program Revisions Adjust to Changing Conditions Original program based on known demand When demand changes existing program becomes invalid Expected arrivals after revision Revised demand

49. Program Revisions Adjust to Changing Conditions Original schedule Expected arrivals after revision Revised demand Original program based on known demand When demand changes existing program becomes invalid Revision of the program reassigns arrival slots to updated demand Balance between demand and capacity is restored Delays are taken on the ground rather than in the air. This is cheaper for the airlines and safer for the flying public.

50. Pre-CDM GDP Process No opportunity for the airlines to solve the problem and avoid the GDP No ability for the FAA to respond to changing conditions with revisions or compressions No smooth transition out of the GDP FAA/Airline Evaluation Demand Vs. Capacity GDP Modeling Send GDP Advisory Issue GDP (Ration by reported demand) Airline Response (Substitutions & Cancellations) Program expires or is cancelled

51. Current CDM GDP Process FAA/Airline Evaluation Demand Vs. Capacity GDP Modeling Send Proposed GDP Advisory Airline Response (cancellations) Is GDP still required? Issue GDP Airline Response (Substitutions & Cancellations) Compression GDP Revision /Extension Yes End No Exit loop when program expires or is cancelled. (Ration by schedule)

52. Collaborative Decision Making Capacity/Demand Management

53. Passengers 60 116 93 87 Total 443 P-DELAY = #PSGR X min DLYD P-Delay min = 26580 P-Delay min =3600 Original P-Delay is 738% greater than revised Passengers 0 CNX 176 (60 late) 93 87

54. Some Perceived Problems Airlines are over-scheduling airports Airlines are withholding delay and cancellation information from the passengers.

55. Over-scheduling? PHX schedules at VFR conditions for certain time frames. –344 days without a GDP from June 2000 to present. –GDP delays range from 60 to 238 minutes –6,192 more scheduled operations, than if scheduled to IFR conditions.

56. Over-scheduling? BOS schedules at VFR conditions for certain time frames. –250 days without a GDP from June 2000 to present. –GDP delays range from 50 to 130 minutes –12,250 more scheduled operations, than if scheduled to IFR conditions.

57. TFM Dependencies Although, the capacity at an airport is reduced and ATC delay has been applied, users may cancel and delay flights as well as notify the FAA of earliest feasible departure times of flights. FAA Actions Cancellations Airline Delays beyond ATC delay Earliest Departure/Arrival Time updates Airline Actions Issue ATC delay Generate Demand

58. Collaboration is Essential to Maximizing Resources When Capacity is Reduced, Airlines Adjust their Schedules by Delaying, Canceling and Substituting Flights. These Schedule Changes are Communicated to the FAA through the CDM Network. The FAA Uses this Information to Maximize Capacity Usage through Revisions, Compressions, and other Delay Reducing Procedures. To Achieve this Efficiency, Departure Times Must Remain Flexible. Delays that are Communicated to the Passengers are difficult to Reduce.

59. Airline and FAA Actions can Reduce Delays

60. Future Steps for CDM Improve Demand-Capacity predictions –Demand Uncertainty –Capacity Uncertainty Improve dynamic resource allocation –User system dependencies –Passenger dependencies Integrated System Solutions –Local versus National Traffic Management Initiatives –Strategic versus Tactical Traffic Management Initiatives