AGIFORS Airline Operations 2005
Technical Program

Anti-trust regulations which require airlines to form their schedules independently can also lead to over-scheduling at airports. Over-scheduling was not foreseen at ORD in 2004, resulting in considerable delay. We propose taking the day of operations, protected data-sharing methods developed under Collaborative Decision Making and modifying them to support evaluation and resolution of airport over-scheduling. The proposed process has three steps: (1) combine all airline schedules in one central repository, determine if delay threshold is exceeded, (2) allow airlines to make adjustments, (3) if step 2 does not resolve issue, only then impose market-based solutions (i.e. slot auctions, congestion pricing).

In this joint study by MIT, Carmen Systems and Lufthansa we model the operations of an airline as a feedback control system and develop a set of parameters or Key Performance Indicators (KPIs) that characterize the inputs to the system (e.g. flight schedule) in terms of their correlation with the outputs of the system (e.g. delays). These KPIs will allow planners and operations controllers to quantify the operational consequences of their decisions. The approach also enables the use of powerful techniques that are commonly used in control theory. The KPIs are being developed with historical and simulation data.

Benchmarking is an effective tool to compare performance with close competitors. If used intelligently can be used as effective management tool to improve and target Airline Performance. However, Airlines should be careful in selecting the 'Right Measures' and more importantly understanding the 'Interdependencies of Various Measures and their cross Influences both +Ve and -Ve'. Fair amount of balancing of these measures is required in driving short term improvements without loosing sight of long term Goal/Vision.

Airport security is becoming an important issue in airline operations. There are several aspects including: obvious security and safety concerns, congestion resulting from airport check-in and transit, checked bag screening, air cargo screening, and other access to the planes such as food vending. We are following several directions: simulation of an airport in terms of all concerns, simulation of passenger flows, design of airports for flows of planes and passengers. The goal is to go beyond modeling congestion to look at design or procedures that will improve security with minimal congestion. Eventual incorporation into SimAir could allow looking at the impact on airline operations due to delays caused by security congestion and breaches.

ALLEGRO SERVICES is collecting the Timestamps of every ground process in FRA and MUC, calculating the individual target model for ground operations by dynamic algorithmes. These results are used at the Hub Control Centers to have an online view on the operation, make investigations and priorities effective to all service partners around the ground handled aircraft.

The assignment of Operations Control within an Airline is to ensure a safe and efficient operation of the published flight schedule. Business drivers in Operations Control are mainly punctuality, regularity and safety. Profitability is covered by network and flight planning. But disruptions will cause changes on the flight plan by Operations Control affecting overall profitability. Analysing standard disruption usecases a concept is developed to support Operations Control with real time cost and revenue figures for each particular change on the actual flight schedule. So alternative decisions between schedule changes and scenarios can be analyzed regarding their impacts on overall efficiency.

What is the minimum data that needs to be collected in a flight following system for effective fuel conservation? What systems are sources for the data? How is the data then best used? A definition of the database is given, how to collect it, how to analyze it, how to identify opportunities for conservation, and how to police the airline effectively. General discussion of fuel conservation takes a holistic view of the airline instead of simply pilot procedures or just getting weight off the aircraft.

A major part of the Ground Handling division budget is personnel cost. Because of the banks, productivity off peak is an issue. Also, legal and industrially negotiated constraints make the relation between workload and staffing complex. We want to provide managers and resource planners with insight in driving forces behind personnel cost, by facilitating what-if analyses on workload covering. Currently we are working on such a tool that invites decision-makers to explore the options beyond their regular assumptions. The tool is based on a mixed integer linear program. This presentation will show the tool and some applications.

Airline’s Operations Management has a crucial role in implementing the Airline Schedule and Route Planning. This will enable Airline to achieve higher revenues while minimizing the total costs and pax inconvenience. There is lot of research work available around this topic and well established applications are today available to Airlines to manage disruptions efficiently. But one would still like to get the answer to the question- “Are we Effective?” in managing disruptions. Did we explore all the options? What is it we can do differently which can improve Effectiveness besides efficiency? This presentation is intended to present some alternate ways and concepts. We may not have ready made solutions/answers to these themes but the intent is to initiate the thinking process, discussion and research work around these concepts.

“Disruption Management in Operations Control” deals with identification of a potential disruption and the “best” recovery strategy. The disruption analysis relies in principle on the quality of integrated real time information which is embedded in information technology and processes. This builds the basis for disruption recovery actions which are only successful if Processes, Information, communication, decision support, Information Technology and recovery objectives are highly integrated. The presentation shows necessary components and possible approaches how to efficiently face Disruption Management initiatives.

Must airlines face operational disruptions on a daily basis that affect aircraft, crew, passenger, maintenance and cargo schedules. In practice, the first problem solved is the recovery of the flight schedule and aircraft routes by the Ops managers. When doing this, their main goal is to be back on schedule as soon as possible with some considerations of the other entities in the system. After the modifications to the flight schedule have been defined, the other players in the OCC (Operational Control Center) come in to the picture to repair the down-line problems namely crew, passenger, maintenance and cargo schedules. The value of using decision support systems to solve these problems individually has been proved multiple times. However, there has been minimal effort on proving the value of integrating these decisions. In this presentation, we show the results of a comprehensive study based on major US airline data that demonstrates that by integrating aircraft and crew decisions the airline can have substantial savings over the independent decisions. We explain the methodology and provide numerical results.

When a major disruption occurs in an airport due to weather conditions or strikes, the OCC or Scheduling departement have to evaluate as fast as possible the impacts of the disruption in order to decide how to return back to schedule. Integrated in the SIROCCO real time system, the goal of the GRS tool is to provide a set of flights to cancel or delay and flight type modifications. The given solution is driven by a user strategy and respects aircraft, crew and passenger constraints so that the overall solution creates less impact for the company.

We use a nested logit estimation to determine the causes of flight delays and cancellations both nationally and at New York LaGuardia Airport (LGA). Previous research on delays and cancellations has treated these decisions as separate and independent events. Using a microlevel data set of post-September 11th flights, we present evidence that airports with dominant carriers do not internalize the delay externality since dominant airport carriers have more delays and cancellations. This suggests that congestion pricing may play a larger role than previously indicated in the literature, especially at airports with dominant carriers.

We explore a novel concept in operations recovery that "looks ahead" at the state of the operations and advises the operations controller of potential issues that may come up if certain actions are not taken. In addition to the advise, a "localized" recommendation for recovery is also provided.

Since aircraft turnaround is complex and critical to schedule dependability, reliable turnarounds are far more important than fast turnarounds. To evaluate current turnaround efficiency, mobile devices (PDAs) are used to record time stamps of key turnaround activities so to help co-ordinate turnaround procedures by different service units. To utilise the mobility of PDAs, a real-time turnaround monitoring system is developed, which reads in time stamps of turnaround activities on a real-time basis via GPRS and runs a simulation model to estimate departure times. A prototype system has been tested and a field trial is scheduled in March with Qantas.

In a ground delay program or a ground stop situation, an airline is required to adjust its flight schedule to comply with imposed operational restrictions. We have studied airline operations recovery under these situations, taking into account key operational areas. For Aeroméxico, we have calibrated the Carmen Integrated Operations Control System (CIOCS) on a number of historic events. To validate the system performance, we have used two Operations Control teams acting in a simulated disruption situation, one using the system and one preparing the solution manually. Using data from a major US airline, we have set up a simulation environment using the MIT Extensible Air Network Simulator (MEANS) and CIOCS to study the recovery during ground delay programs. We will report preliminary findings of this exercise.

Airline Operations involve many extraneous factors that are beyond the scope of traditional optimization and require user intervention. Consequently, one of the biggest challenges in introducing optimization into Airline Operations is winning the trust of the users and then entrusting them with the power to drive the optimization models. This presentation lists out various challenges that United Airlines encountered while gaining wider acceptance for Optimization in the Day-of-Operations area. We specifically talk about Irregular Operations and share ideas that help address them.

The problem of standardizing of flight operation performance metrics from user perspective but especially from airline network dynamics has already received adequate attention,but due to high level of complexity and random nature of operation environment there is still lack of industry accepted metrics of the quality of the whole process.Proposed methodology is based on the concept of the marginal cost of speed of flight realization as an indicator of quality of optimization of the process measured against aircraft performance characteristic and the characteristic of access to airspace.

The OCC Forecaster overcomes the limitations of the traditional Gantt chart. It computes a dependency network of all resources in the operational schedule and predicts downline delays. The network is checked for follow-on effects caused by weather, airport, aircraft or crew constraints which puts allow operations control and crew tracking in a position to avoid disruptions in an early stage by resolving the root-cause of a whole set of problems.

More and more airports plan to approach the capacity problem by means of Predeparture Sequencing, also known as Departure Management (DMAN). In that process, optimised target offblock times (TOBTs) are assigned to flights in order to achieve an optimised departure sequence at the runways. But how do factors such as taxi time variation, runway topology and resource conflicts at the gates affect the expected benefits in throughput, taxi time and takeoff punctuality? The answer is presented on the example of Frankfurt Airport, identifying critical success factors and introducing possibilities to alleviate their impact.

We look at the problem of reaccommodating passengers for real-time day of operations disruptions as well as schedule changes for revenue management. Potential issues that arise due to the large volume of data are discussed and modeling strategies to counter them are elaborated.

Real-time operations as Crew Tracking and Operations Control easily create more information than the users can handle. In a situation like a major disruption, massive amounts of information are sent to the user via several channels, making it difficult to find the right information in the flow. We will present a solution to the information overflow problem by implementing the Details-on-Demand concept where dashboards, alert monitors, interactive reports and detailed Gantt Charts display different views of the same data, letting the user be in control by browsing the information flow and adapting the detail level to the situation.

Airlines currently have little influence on tactical arrival planning. However airline operations and cost depend heavily on these decisions (especially during airport arrival capacity deficiency). A method will be presented to schedule aircraft landings, taking airlines' cost into account. Airlines must supply a cost function for each arriving flight. Using these, the decision on landing times will reflect the economic trade-off for airlines. Of course it also provides a safe and efficient arrival schedule, and it takes into account equity between airlines.

A key objective of the Southwest Airlines Tactical Aircraft Routing and Recovery (STARR) initiative is to help Dispatch fulfill near-term maintenance plans and execute the published schedule. Dispatch Superintendents On Duty (SODs) are responsible for routing aircraft into maintenance for work due in the next 7 days and balancing the total work load among the various maintenance locations. SODs are also responsible for recovering the planned aircraft-to-route assignments when disruptions, like mechanical failure or bad weather, arise on the day of operation. In order to achieve these two goals, STARR divides the entire assignment horizon into the near-term "Tactical Routing" and "Recovery" horizons. In the Tactical Routing horizon, aircraft are assigned to routes consistent with the maintenance visits planned for these aircraft taking into consideration maintenance constraints like flexible completion dates or locations, hangar slots and labor hours. In the Recovery horizon, these routings are maintained (or reassembled) with the goal of minimizing disruption to passengers, crew and cargo. In this presentation, we discuss our development of the Tactical Routing Optimizer both as a stand-alone solution for tactical aircraft routing an as the foundation for the eventual day of operations Recovery Optimizer.

Today the core business components of scheduling, operations control and crew management systems more and more follow the motto “Maximizing the Benefits of Integrated Operations”. They are focussed on a workflow oriented and integrated approach. Now, the next era will be workflow oriented and fully integrated optimization tools. This address a vertical integration between aircraft and crew resource optimization, as well as horizontal integration of the workflow between different business processes.

For more details on the Crew Management technical program, please visit:
www.agifors.org/studygrp/crewmgt/2005/abstracts.html