1Giovanni Andreatta Padova University Verona 18 maggio 2006

Operations Researchin

Air Transportation

2Giovanni Andreatta Padova University Verona 18 maggio 2006

Air Transportation System

InfrastructureAirportsATM (Air Traffic Management)

ATFM (AT Flow Management)ATC (AT Control)

SuperstructureCommercial FlightsPrivate FlightsMilitary Flights

3Giovanni Andreatta Padova University Verona 18 maggio 2006

Eurocontrol ATFM area and an example of Sectorization

4Giovanni 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

5Giovanni 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 FlightCDM (Collaborative Decision Making)

and tools, for example:COMPASMAESTROCTAS

6Giovanni 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)

7Giovanni 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.

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Example of GUI

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Over 95% of the total EUROCONTROL

Route charges revenues

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Forecasted no. of IFR flights in CFMU area

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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)

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ATFM

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ATFM

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First solution: Ground Holding

Ground holding safer than airborne holding

Ground holding cheaper than airborne holding

N.B.: Flight shift in time

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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

17Giovanni 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 USA30,000 flights in Eurocontrol zone

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Ground Holding Problem

MIT

Padova University

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GH model(meaning)

MIN Total Cost of (ground + airborne delays)

subject to: Capacity constraints Assignment constraints Coupling constraints Integrality constraints

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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

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Rerouting

€ €

€ € €

€

€

A rerouting is sometimes imposed by CFMU.

Rerouting implies different route charges!

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EUROCONTROLroute charge formula

n

irRTotal cost:

Unit rate in State i

iii tMTOW

dr 50

where for each State i the charge is given by:

Distance traveled in State i

23Giovanni Andreatta Padova University Verona 18 maggio 2006

Critics to EUROCONTROL 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 …

50/** MTOWDRFee

24Giovanni 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.

25Giovanni 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/

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IRCS Specific Issues (partial list)

Alternative charging formulaeCommon unit rateTwo-part charge, etc.

Impacts of alternative charging systems Charge according to flight plan Tax on tickets Containment of service provider costs Other?

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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

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Market based

Flow Demand Management

and Rerouting

Odoni, Fan, … (MIT)

Andreatta, Lulli (Padova)

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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

d

dWcWc

d

dCMC q

q

= +

30Giovanni 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?

31Giovanni Andreatta Padova University Verona 18 maggio 2006

Airports

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Airport modeling

Landside (Passenger terminal) Baggage handling Apron stand allocation Arrival aircraft sequencing

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Airport landside modeling

European sponsored projects: IV UE framework program: “TAPE” V UE framework program: “OPAL” VI UE framework program: “SPADE”

Padova UniversityRome “La Sapienza” UniversityAthens AUEBToulouse ONERADelft University

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SLAM ImplementationSLAM Implementation

• Program: ANSI C, LEX and YACC

• Graphic User Interface: JAVA

• Run under UNIX and WINDOWS

run

Input file Output fileOutput file

Output file

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Apron stand allocation

Romanin-Jacur, Filippi

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Arrival aircraft sequencing

Bianco, Rinaldi, Dell’Olmo, Lulli, …

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AIRLINES

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Airlines

Deregulation and Liberalization drive a higher competition

Need to reduce costs

Need to enhance revenues

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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

40Giovanni Andreatta Padova University Verona 18 maggio 2006

Airlines revenues

Revenue management Seat pricing Seat categorization Integration

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Optimization Methods

Integer Linear Programming Greedy algorithms Genetic algorithms Tabu search Bi-linear programming models

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Where in the USA ?

NEXTORMITVirginia TECHU. of MarylandUC BerkeleyGMUFAA

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Where in Italy

PadovaAndreatta, Brunetta, Lulli, Romanin-Jacur,

… Rome

Dell’Olmo, Bianco, … Trieste

Ukovich, Castelli, Pesenti, … Siena

Marti

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Thank You

Padova References: www.dei.unipd.it/~brunetta/at_papers/

45Giovanni Andreatta Padova University Verona 18 maggio 2006