1. John-Paul Clarke:  Robust Scheduling

Robust scheduling is an important area in airline OR because increased passenger and cargo demand has not been met by increased airport and airspace capacity, resulting in significant and costly delays and disruptions. We present several ideas for improving the robustness of airline schedules and quantify their potential benefits through analysis and simulation. Ideas include: aircraft routings where ground times are proportional to expected upstream delay; flight departure times that factor in expected upstream delays of aircraft, crew and passengers; independent layering of schedules to prevent delay propagation and provide guaranteed, high-reliability service for a "desired" subset of the itineraries.

2. Anwar Hood Ahmed: Schedule Robustness

Optimization application has revolutionized the airline industry in all phases of the planning process. One of the current issues facing the airline industry is planning under uncertainty, especially in the context of schedule disruptions. We discuss the robust models and solution algorithms that have been proposed and developed to handle the uncertainty. We show that stochastic programming provide an ideal paradigm for capturing uncertainties and making robust decisions.

3. Jasenka Rapajic: Hidden Costs of Airline Operations

Airline industry still doesn't have a recognised tool to accurately monitor and report on root causes of operational disruptions and their costs and impact on revenue. Internal reasons hidden behind departmental strongholds are especially difficult to identify, leaving airline executives deprived of vital information about the effectiveness of their product plans. Iceberg project, a winner of DTI's Smart Award focuses on prioritising risk areas by identifying underlying causes of disruptions and their costs, bringing accountability for operational performance to the corporate level, which is best able to determine what trade-offs between quality and cost are acceptable for managing expectation of future results.

4. John-Paul Clarke:  MEANS: A Tool for Evaluating Schedule Robustness and Reliability

Schedule reliability is a concern for all airlines. However, there are few tools to evaluate schedule robustness and reliability a priori, and thereby improve schedule design. MEANS is a model of the U.S. and European air transportation networks in which air traffic service provider and airline decision making, the impacts of weather on airport capacity and decision making, the effects of stochastic phenomenon, and the movement of aircraft, crews, and passengers are simulated. We present a description of the model and examples of its use in the evaluation of schedule robustness and reliability.

5. Yu Zhang: Realtime Intermodal Substitution as an Airport Congestion Management Strategy

We explore the potential for inter-modal substitution to reduce flight traffic and reduce delays in situations where there is a temporary shortfall in airport capacity. In our scheme, airlines cancel short-haul flights and rebook passengers on surface transport modes in cases when the delay savings from reduced flight traffic is greater than the costs and increased travel time associated with the surface mode. We demonstrate a simple optimization model that chooses which flights to cancel, as well as a more complex model that considers missed connections, surface vehicle routing, and other issues.

6. Ellis Johnson: Schedule analysis and a duty partition model for crew scheduling

Schedule analysis, without intensive computational efforts, can evaluate the crew friendliness of a schedule and suggest improvements when the evaluation is poor. The minimum number of duties is an important index. Moreover, duty patterns and pairing patterns are investigated for domestic problems. A duty partition model is proposed according to these analyses. Instead of using pairing variables, duties are defined as decision variables. The duty network incorporates legalities for pairings. Computational results show that it is fast and can approach the optimal pairing solution. Possibilities of extending this model to achieve robust planning and integrated planning with fleet assignment are discussed.

7. Daniel Sallier: An innovative approach to estimate demand elasticity

Aéroport de Paris' passenger demand forecasting models are based on the Kenza methodology initially developed by Airbus Industry and tested with the airlines since 1995. Since it is not an econometrical approach, demand elasticity to fares, GDP and demographic growth are model results and are not assumptions to be entered into the set of demand equations. A direct consequence of this approach is to provide the demand elasticity evolution over the time and to provide clues on its anticipated changes. The presentation item are: - a quick presentation of the Kenza demand forecasting method; - calculation of the demand curve; - calculation of demand elasticity; - illustrations with some markets served from Paris; - a market diagnostic tool

8. Chikage Miyoshi : Key determinants of competition

Competition does not exist only between airlines but also with other modes of transport. In Japan the high- speed railway network has been developed since 1964. The more each transport mode has expanded, the more passengers’ choice has been expanded. The factors that attract customers become critical in a competitive market. This study attempts to examine the effects of competition between air transport and high-speed rail in order to find the key determinants of competition and evaluate them as key factors of Customer Value using Structural Equation Modelling.

9. Olaf Jeschke: Optimizing Hub Systems with operational constraints

For all network carriers operating one or several hubs, it is crucial to offer optimal connections through their hubs. Since most of the hubs are heavily congested, an optimal usage of the available slots at the airports is highly important. Besides considering the slots, the existing aircraft rotations must be conserved in order to keep the schedule feasible. If more than one hub is operated, the coordination of competing connections in several hubs adds another layer of complexity to the optimization process.

10. Dirk Guenther: Network Manager A Tool for Schedule Generation

We present a system for Schedule Generation. The system consists of two components, one to generate a schedule structure and one to re-time flights in an existing structure. Both modules together allow us to optimize fleet size, service frequency, fleeting, and flight timing while considering limits on fleet size and service frequencies as well as market share targets.

11. Kostas Iatrou: An attempt to measure the traffic impact of airline alliances

This paper analyzes the effects of airline alliances on the allied partners’ ouput by comparing the traffic change observed between the pre- and the post-alliance period. First, a simple methodology based on traffic passenger modelling is developed, and then an empirical analysis is conducted using time series from four global strategic alliances (Wings, Star Alliance, oneworld and SkyTeam) and 124 alliance routes. The analysis concludes that, all other things being equal, strategic alliances do lead to a 9.4%, on average, improvement in passenger volume.

12. Matthew Berge: Collaborative Arrival Management

Full abstract to follow in mid-April subject to required approval process. Briefly ...The presentation will describe modeling and analysis of arrival sequencing, scheduling, and runway assignment with a focus on the benefits of ATC-Airline collaboration.

13. Matthew Berge: Airline Schedule Recovery in Collaborative Flow Management

Full abstract to follow in mid-April subject to required approval process. Very briefly ...The presentation will describe modeling and analysis of airline schedule recovery in the face of disruptive events such as convective weather.

13. Barry Smith.  Integrating fleet assignment modeling and revenue management

Airline profitability can be improved if fleet assignment models better anticipate the impact of subsequent marketing actions on revenue and traffic.  We review approaches to integrating fleet assignment models and revenue management as well as recent computational results.  

14. Maximilian M. Etschmaier : From “Airline Schedule Development And Evaluation”To “Airline (Strategic) Service Planning”

In the 1960’s the airline environment went through a radical transformation. In response, the process of “airline schedule development and evaluation” was developed. Since then, the airline environment again has undergone a radical transformation. Many models and methods have been adapted and developed to help with many of the decisions required in the new environment.   In this paper we will identify the concepts that prompted the emergence of the airline schedule development and evaluation process, and show how they bear on the situation today. We will argue that, today, what used to be airline schedule development and evaluation might be better viewed as airline (strategic) service planning, and provide snapshots of an overall framework. Key elements of the framework will be: a hierarchy for the decision-making process, balancing the significance of all resources, decomposition, aggregate planning, and human-machine symbiotic cognition.

The Conference welcomes all qualified papers on scheduling and strategic planning concepts and methodology. If you are interested in presenting at the study group meeting, present submit your abstract online at this url: http://www.agifors.org/studygrp/ssp/2006/present.html

General Information

Please contact Lisa Noell for any additional information, and/or clarification on the AGIFORS Strategic and Schedule Planning 2006 study group meeting.

email     Lisa Noell
phone   +1 817-931-7287

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