1. 1 Giovanni Andreatta Padova University Verona 18 maggio 2006 Operations Research in Air Transportation

2. 2 Giovanni Andreatta Padova University Verona 18 maggio 2006 Air Transportation System Infrastructure Airports ATM (Air Traffic Management) ATFM (AT Flow Management) ATC (AT Control) Superstructure Commercial Flights Private Flights Military Flights

3. 3 Giovanni Andreatta Padova University Verona 18 maggio 2006 Eurocontrol ATFM area and an example of Sectorization

4. 4 Giovanni Andreatta Padova University Verona 18 maggio 2006 ATM (AT Management) Motivation for improvement New technologies CNS (Communications Navigation Surveillance) Datalink Better weather forecasting New economic framework Deregulation Liberalization Competition

5. 5 Giovanni Andreatta Padova University Verona 18 maggio 2006 Aviation Authorities (ICAO, FAA, Eurocontrol, National Aviation Authorities) are adopting new ATM concepts: FANS (Future Air Navigation System) Free Flight CDM (Collaborative Decision Making) and tools, for example: COMPAS MAESTRO CTAS

6. 6 Giovanni Andreatta Padova University Verona 18 maggio 2006 SAFETY Primary objective of ATM system Same separation rules in the last 15 years (except for vertical separation …) Lack of quantitative models Need for a greater flexibility Implementation of new concepts requires careful examination (example: implications of Free Flight)

7. 7 Giovanni Andreatta Padova University Verona 18 maggio 2006 ATFM (AT Flow Management) Providers FAA Eurocontrol CFMU (Central Flow Management Unit) ATM is continuously evolving Excellent information, elaboration and visualization capabilities Lack of satisfactory decision support systems Need for real time tools able to handle uncertainties (e.g., weather) and dynamically changing reality.

8. 8 Giovanni Andreatta Padova University Verona 18 maggio 2006 Example of GUI

9. 9 Giovanni Andreatta Padova University Verona 18 maggio 2006 Over 95% of the total EUROCONTROL Route charges revenues

10. 10 Giovanni Andreatta Padova University Verona 18 maggio 2006 Forecasted no. of IFR flights in CFMU area

11. 11 Giovanni Andreatta Padova University Verona 18 maggio 2006

12. 12 Giovanni Andreatta Padova University Verona 18 maggio 2006 ATFM Demand Scheduled flights Charter flights General Aviation Military flights State flights … System Capacity Airports (number of take-off/landings) Airways Sectors (no. of flights entering the sector or no. of flights in the sector)

13. 13 Giovanni Andreatta Padova University Verona 18 maggio 2006 ATFM

14. 14 Giovanni Andreatta Padova University Verona 18 maggio 2006 ATFM

15. 15 Giovanni Andreatta Padova University Verona 18 maggio 2006 First solution: Ground Holding Ground holding safer than airborne holding Ground holding cheaper than airborne holding N.B.: Flight shift in time

16. 16 Giovanni Andreatta Padova University Verona 18 maggio 2006 Second solution: Rerouting It is sometimes directly imposed by the Aviation Authority (CFMU) Could be in-directly imposed: air traffic demand management N.B.: flight shift in space

17. 17 Giovanni Andreatta Padova University Verona 18 maggio 2006 Ground Holding Ground holding better than airborne delay History: 1981 USA AT controllers strike Dimensions (No. of daily flights): 60,000 domestic flights in USA 30,000 flights in Eurocontrol zone

18. 18 Giovanni Andreatta Padova University Verona 18 maggio 2006 Ground Holding Problem MIT Padova University

19. 19 Giovanni Andreatta Padova University Verona 18 maggio 2006 GH model (meaning) MIN Total Cost of (ground + airborne delays) subject to: Capacity constraints Assignment constraints Coupling constraints Integrality constraints

20. 20 Giovanni Andreatta Padova University Verona 18 maggio 2006 GH model (type and dimensions) The resulting model is a MIP (Mixed Integer Programming) problem with a few hundred thousands boolean variables and constraints The problem is NP-hard (i.e., difficult) Yet, the instances using real data were easy to solve

21. 21 Giovanni Andreatta Padova University Verona 18 maggio 2006 Rerouting A rerouting is sometimes imposed by CFMU. Rerouting implies different route charges!

22. 22 Giovanni Andreatta Padova University Verona 18 maggio 2006 EUROCONTROL route charge formula Total cost: Unit rate in State i where for each State i the charge is given by: Distance traveled in State i

23. 23 Giovanni Andreatta Padova University Verona 18 maggio 2006 Critics to E UROCONTROL formula: Should better reflect actual ATC costs: Use time rather than distance? Question the importance of weight (augment the exponent from 0.5 to 0.87 ?) Efficiency in providing ATC services should be taken into account …

24. 24 Giovanni Andreatta Padova University Verona 18 maggio 2006 Air Navigation and Airport User Charges Great interest internationally Background of rising infrastructure costs and security costs at a time of global industry crisis Multiple objectives for charging systems: Cover costs of service providers Cost-related charging formulae Provide incentives to improve efficiency/performance of service providers Inform prioritization of investments Promote operational efficiency (e.g., reduce congestion) Transparency and user participation etc.

25. 25 Giovanni Andreatta Padova University Verona 18 maggio 2006 IRCS project (Trieste + Padova) Innovative Route Charging Schemes For more information see: www.eurocontrol.int/care/innovative/projects2002/ircs/

26. 26 Giovanni Andreatta Padova University Verona 18 maggio 2006 IRCS Specific Issues (partial list) Alternative charging formulae Common unit rate Two-part charge, etc. Impacts of alternative charging systems Charge according to flight plan Tax on tickets Containment of service provider costs Other?

27. 27 Giovanni Andreatta Padova University Verona 18 maggio 2006 General aim of IRCS project the final purpose of the Innovative Route Charging Schemes project is: to study the impact of changes in en- route charges with respect to the demand and supply sides of ATM in a view to improve the overall efficiency of the system

28. 28 Giovanni Andreatta Padova University Verona 18 maggio 2006 Market based Flow Demand Management and Rerouting Odoni, Fan, … (MIT) Andreatta, Lulli (Padova)

29. 29 Giovanni Andreatta Padova University Verona 18 maggio 2006 Optimal congestion fee A congestion fee on a user is optimal when it is equal to the external costs that the user imposes on the other users. For a M/G/1 queue: Marginal Internal External cost cost cost = +

30. 30 Giovanni Andreatta Padova University Verona 18 maggio 2006 Idea under investigation Without congestion fee, BIG aircraft are penalized With optimal congestion fee, SMALL aircraft are penalized Why not consider different categories and compute the external cost imposed within each category?

31. 31 Giovanni Andreatta Padova University Verona 18 maggio 2006 Airports

32. 32 Giovanni Andreatta Padova University Verona 18 maggio 2006 Airport modeling Landside (Passenger terminal) Baggage handling Apron stand allocation Arrival aircraft sequencing

33. 33 Giovanni Andreatta Padova University Verona 18 maggio 2006 Airport landside modeling European sponsored projects: IV UE framework program: TAPE V UE framework program: OPAL VI UE framework program: SPADE Padova University Rome La Sapienza University Athens AUEB Toulouse ONERA Delft University

34. 34 Giovanni Andreatta Padova University Verona 18 maggio 2006 SLAM Implementation Program: ANSI C, LEX and YACC Graphic User Interface: JAVA Run under UNIX and WINDOWS run Input file Output file

35. 35 Giovanni Andreatta Padova University Verona 18 maggio 2006 Apron stand allocation Romanin-Jacur, Filippi

36. 36 Giovanni Andreatta Padova University Verona 18 maggio 2006 Arrival aircraft sequencing Bianco, Rinaldi, DellOlmo, Lulli, …

37. 37 Giovanni Andreatta Padova University Verona 18 maggio 2006 AIRLINES

38. 38 Giovanni Andreatta Padova University Verona 18 maggio 2006 Airlines Deregulation and Liberalization drive a higher competition Need to reduce costs Need to enhance revenues

39. 39 Giovanni Andreatta Padova University Verona 18 maggio 2006 Airlines costs The Passenger Mix Model The Fleet Assignment Problem The Crew Pairing Problem, the Aircraft Routing Problem, and the Integrated Crew Pairing-Aircraft Routing Problem The Schedule Design Problem Integrated Models

40. 40 Giovanni Andreatta Padova University Verona 18 maggio 2006 Airlines revenues Revenue management Seat pricing Seat categorization Integration

41. 41 Giovanni Andreatta Padova University Verona 18 maggio 2006 Optimization Methods Integer Linear Programming Greedy algorithms Genetic algorithms Tabu search Bi-linear programming models

42. 42 Giovanni Andreatta Padova University Verona 18 maggio 2006 Where in the USA ? NEXTOR MIT Virginia TECH U. of Maryland UC Berkeley GMU FAA

43. 43 Giovanni Andreatta Padova University Verona 18 maggio 2006 Where in Italy Padova Andreatta, Brunetta, Lulli, Romanin-Jacur, … Rome DellOlmo, Bianco, … Trieste Ukovich, Castelli, Pesenti, … Siena Marti

44. 44 Giovanni Andreatta Padova University Verona 18 maggio 2006 Thank You Padova References: www.dei.unipd.it/~brunetta/at_papers/

45. 45 Giovanni Andreatta Padova University Verona 18 maggio 2006