TPAC Disruption Management

TPAC^TM Disruption Management is part of the TPAC^TM suite of planning tools. It is used to manage disruptions that occur on the day of operations. The objective of the TPAC^TM Disruption Management Optimizer is to assist operations control staff in the discovery of and recovery from modifications to the published schedule on the day of operations, in order to minimize disruptions as they occur.

What is Disruption Management?

On the day of operations, delays, cancellations and closures will result in increased crewing costs, aircraft running costs and changes to the schedule. Disruption management is the response to these problems which gives a swift recovery to the planned operation. Typically it consists of the following steps:

• situational awareness: to understand the current situation and determine if schedule recovery is required
• creation and evaluation of recovery scenarios
• publishing of updates to the schedule. Each operator performs disruption management for their own fleets and crews within limits set by the network controller.

Disruption management has been the subject of extensive research and development over the past 20 years. The best results can only be achieved when fleet, crew, passengers, freight and scheduled maintenance are integrated into a single real time decision support tool that allows rapid visualization of the current situation and the effects of any planned recovery.

What are the Challenges in Disruption Management?

The key difference between Disruption Management and other types of optimization is that it aims to not only be an optimizer, but also a decision support system. Solving a problem in seconds allows the operator to resolve mission critical issues in real time during the day of operations.

The key challenges in Disruption Management are:

• To serve as both an optimization engine and a decision support system. Optimization algorithms are highly complex and can take several hours to run, whereas decision support requires real time processing.
• To integrate with systems used by operators on the day of operations. Different organizations face different problems, and use different operating environments. Disruption management needs to interface with these operating environments, and need to be customized for each organization's particular problems.
• Solutions need to not only solve the immediate problem but should also not create further problems down the track.

You can read an interesting article written by CTI's Vice President of Architecture and Research Ian Evans here.

How is TPAC Disruption Management Optimizer used?

The TPAC^TM Disruption Management Optimizer has been designed to handle all disruption management requirements for a transport enterprise, including:

• Passenger impact
• Crew impact
• Maintenance impact
• Airport movement slots, gates, and terminal space impacts
• Aircraft costs impact
• Configurable costs including "What if" analysis
• Detailed graphical analyzes of solutions

If a resource becomes unserviceable the TPAC^TM Disruption Management Optimizer works out several different solutions for this problem and presents them to the user. Each solution is ranked according to their weighted costs. The user can graphically visualize the changes to the schedule on a Gantt chart for each solution, and also view a detailed breakdown of their changes and costs.

Advantages of TPAC Disruption Management Optimizer

The TPAC^TM Disruption Management Optimizer has the following advantages:

• Manual solutions usually do not consider cost well, since rules of thumb tend to gravitate toward solutions that work in a broad range of situations; these can stray far from solutions that are optimal to a particular disruption.
• It is not easy to find good solutions to large disruptions such as port closures or extended resource unavailability. Furthermore, missed opportunities for faster recovery may occur as it is difficult to manually consider complex problems.

User Interface

The user interface TPAC^TM Workbench allows the user to perform a number of optimization runs each with different run parameters and to then compare the results to select the run with the desired outcome. Multiple simultaneous runs can be performed, and run progress can be monitored in real time. Runs can be scheduled to maximize the usage of available hardware. Runs can be monitored with "live graphs" to assess the quality of a solution before the run has completed. Results from an optimization run can also be edited to create a final solution or to "warm start" another optimization run.

Performance

Solutions to disruptions are obtained in seconds for simple problem sets and minutes for complex problem sets, allowing the user to make decisions regarding possible changes to the schedule in real time.

Architecture

TPAC^TM Disruption Management is a Unix based technology that harnesses the power of FICO's Xpress optimizer. TPAC^TM Disruption Management is made available through the TPAC Framework that includes:

• TPAC^TM Workbench -- A Java-based graphical user interface designed to support analysis, editing and interaction with our optimizers on any desktop environment.
• TPAC^TM Connect -- A web enabled remote access and systems integration platform.
• TPAC^TM Rules -- A common rules repository designed to assure consistency of business rules across the enterprise.
• TPAC^TM Reports -- A reports package with a library of common charts and metrics that can be customized and expanded upon.