The U.S. Inspector General reported in 2000 that 27.5% of flights were delayed, cancelled, or diverted, affecting 163 million passengers. The implementation of the CrewSolver system has helped airlines mitigate this, working to maximize expected revenue and minimize operational costs. As an advanced DSS, CrewSolver helps crew schedulers and dispatchers produce desirable recovery solutions quickly. This helps airlines avoid additional delays and cancellations, improve their on-time performance, reduce the number of passengers to re-accommodate, and preserve passenger goodwill. According to a friend of mine who flies for Continental out of Newark (EWR), irregular operations can be anything from bad weather (which is the primary disruption), to air traffic control-mandated changes, to crew unavailability, all made even more difficult by high traffic volume at many airports. Flying out of the New York and Philadelphia areas, major disruptions are almost the norm, so a dynamic crew recovery system is imperative, especially for Continental, whose main hubs are in Newark and Houston.
Dr. Gang Yu founded CALEB™ Technologies Corp. in 1994 to develop Advanced Integrated Real-time Decision Support Systems ™ (AiRDSS) for complex, real world business problems. Working together with Continental Airlines, CALEB Tech developed the CrewSolver system. Other airlines had been working to develop similar systems, but CrewSolver was the first system to successful integrate such high levels on information and produce solutions in a time-sensitive manner. The system was implemented in late 2000, and Continental saw immediate results. After success Continental saw with dealing with the aftermath of September 11 th , interest in the system grew. More on the CrewSolver role in post-9/11 flight recovery will be discussed later in the presentation. CrewSolver subsequently has been adopted into other airlines’ systems. It is used extensively today in combination with other airline operations management systems.
(Though multiple airlines now use CrewSolver technology, this presentation focuses strictly on Continental Airlines, as they were the company who produced and first utilized it.) Continental Airlines has more than 50,000 employees, including 4,000 pilots and 8,000 flight attendants (as of 2003). A goal of the company is to &quot;treat both the internal and external customer with dignity and respect,” and minimization of cancellations and delays due to crew problems fits in well with this idea.
During a major Northeast snowstorm—dubbed by some as “the storm of the century”– it took Continental Airlines days to figure out where all of its crews were. Most flight crews tried to call in to the operations center but found the phone lines consistently busy, and there was no other means of communication. During that period, Continental completely lost control of its operations, which meant numerous cancelled flights and lost revenue. This prompted the airline to look into an integrated IT system with real-time decision support in crew management and aircraft routing to support its SOCC (Systems Operations Coordination Center). At that time, no such system existed at that time, and they determined one had to be designed from scratch. Gang Yu, founder of CALEB worked with the airline to develop a prototype which could generate solutions in seconds for reasonably sized problems that might take personnel manually more than thirty minutes. Continental realized that developing such a system would reduce operational costs and improve its overall reliability, which in turn would help them turn their business around and offer them a significant competitive edge.
* DEFINITIONS : - ATC - Air Traffic Control - crew - - The term &quot;crew&quot; refers to both pilots and flight attendants, though pilots have more restrictions (pilots, for example, are qualified to fly specific aircraft types, whereas flight attendants can work on multiple types). Therefore, crew scheduling is harder than plane scheduling - crew-pairing - a sequence of flight legs beginning and ending at a crew base that satisfies all governmental and contractual restrictions (also called legalities) - deadheading - the practice of moving crews on flights as passengers, used to reposition flight crews. According to my pilot friend, deadheading is a very frequent operation; sometimes at a loss to the airline, as a passenger must be bumped and re-accommodated - OpsSolver - the plane recovery system that airlines use in concert with CrewSolver - sit crew – Crews assigned to reserve duty who must sit in full uniform at the airport and be available for flight within 15 minutes’ notice Airlines have a significant number of factors to keep in mind (see above) when rescheduling. Crew and Flight Operations managers must weigh factors like re-accommodating passengers, the impacts on crews, and aircraft maintenance requirements when making changes to flight schedules for a feasible and desirable recovery plan. If a flight must be cancelled or rescheduled, the airline is responsible for booking passengers on other flights, paying crew overtime, and/or covering the cost of crew and passenger overnight accommodations.
CALEB Technologies (CALEB stands for Computer Applications in Logistics Engineering and Business) work together for efficient and expeditious recovery and rescheduling services. Having systems that are interconnected makes the decision-making process much easier and enables various sectors to remain up-to-the-minute on operations. For more information on CALEB Technologies products, visit http://www.calebtech.com. The CrewSolver optimization server has an in-memory data store maintaining the status of current operations. This system interacts with the other systems to keep updated information on overall systems operations. The system internalizes the data store with live operational data from the system operations control (SOC) database, crew data retrieved from mainframe system, data maintained in electronic data files. This integrated system streamlines information for crew and operations schedulers quickly.
If a pilot becomes ill, misses a connection, is stranded, or encounters some other issue which prevents him or her from completing a flight cycle, the airline needs to find a new QUALIFIED pilot to cover the flight(s). Pilots are usually qualified for one position: captain, first officer, or second officer/flight engineer and also only fly specific routes and airports. For this reason, a set number of crew are kept on reserve, whether on reserve or in the airport &quot;sitting hot.” This information is part of what is entered into the crew-recovery system on the day of operations. In resolving crew disruptions, the coordinators use the CrewSolver system whenever a crew-recovery solution is not immediately obvious. The CrewSolver system promotes what-if analysis, allowing the airline to easily and quickly examine different scenarios before making decisions that concern large sums of money. This allows them to develop flight delay and cancellation strategies so that they can take proposed changes and determine crew impact, something they could not do before the system was implemented because of the size of the problem and the time it involved.
CrewSolver uses all three of Mintzberg’s models. “Thinking first” is appropriate because the DSS is working with reliable and (mostly) structured data, and “seeing first” works because the companies using the software are dedicated to finding cost efficient and effective solutions. The way that CrewSolver is tied in with other DSSs (dealing with plane and schedule operations) show that the companies involved are also dedicated to inter-departmental communications. Working with all three of these models, the CrewSolver DSS offers constructive decision options.
CrewSolver’s return on investment (ROI) was estimated to be within 8 months and has saved Continental Airlines millions of dollars each year for the past decade. CrewSolver’s ability to reduce crew-caused delays, cancellations and reserves on day-to-day disruptions can conservatively save a major airline more than $10 million each year. For major disruptions, CrewSolver can save in excess of $2 million per occurrence.
For the major airlines, crew costs are the second-largest component of direct operating costs after fuel. By maintaining good control over crew operations, CrewSolver saves the company money by reducing en route and pre-departure delays. The system gives solutions that yield fewer minutes per delay, fewer cancellations, fewer ferry flights and diversions, less wasted fuel, and savings on crew penalties, hotel, and per diem savings. The savings come mostly from avoiding flight cancellations due to crew unavailability. Additionally, the ability to wait until it has more accurate weather data also permits Continental to avoid unnecessary cancellations. Minimizing crew and plane operations issues simultaneously can drastically reduce the time it takes to return to normal operations. This time reduction results in less financial disruption and maintains passenger satisfaction.
The system updates the data using messages from a message server. A crew coordinator uses a graphical user interface (GUI) to request the optimization server to provide a recovery solution. The optimization server sets up a probable scenario based on the data the user inputs and the in-memory data store. The solver then generates up to three solutions. Crew schedulers must consider the pros and cons of the following based on the solutions the CrewSolver system offers: - reassigning crews - deadheading crews - holding crews at current location - assigning crews additional duty periods - moving a crew's layover to a different city - using crew reserves to cover flights uncovered by active crews
The CrewSolver system receives information about the initial flight schedule and current status information for a set of disrupted flights. When a disruption occurs, the optimization engine calculates up to three optimal solutions (the intent is to minimize the total cost involved in covering scheduled flights while also limiting disruptive impact to the airline and to the crew members). The system offers partial solutions along with multiple full solutions; the impact of a particular solution is displayed by crew number affected according to various criteria ( see above right image ). The solutions offered are those that make sense operationally, and offering multiple solutions takes into account the fact that there might be some factors that the recovery system is not aware of (this underscores the need for human input in the decision process). This process of using a DSS enables people to use their experience and knowledge in evaluating the alternatives before committing to a solution that will have wide-reaching impact. Because it does not offer a definitive solution, the multiple solution approach relies on crew coordinators to manage the extraordinary situations that cannot be embedded in the optimization model. CrewSolver is merely an aid in the decision-making process.
I say “ideally” here because my pilot friend has noted that as a for-profit company, the bottom line of the company is financial—and that means that crews sometimes bear the burden as their needs and benefits are placed lower. The implementation of CrewSolver in airline operations helps to keep things standardized and can minimize system disruptions, but because human involvement is still a major part of the ultimate decision process, there is room for error, especially where legalities are involved (most especially crew members not being able to work more than a 16-hour shift). Still, it has helped airlines tremendously in the past decade.
Example : According to my pilot friend, overrides to manipulate schedules around the 16-hour day maximum are quite common. These changes to the schedule have a dramatic impact on crew pay and quality of life: “ Person X is sitting at home on reserve and Pilot A calls out sick. Schedulers go through their list of reserve pilots and call up Person X, who has been sitting on reserve at home since 10 am and scheduled to do so till 10PM. He gets a call at 10:30 AM telling him to report for duty at 9:30 PM for a 10:30 PM departure. What this then means is that he would be on duty for 12 hours already (10 AM – 10 PM) and would only have 4 hours to spare when his plane departs for this out and back (flight to an airport then back to Newark). The CrewSolver system then comes up with an idea to declare Pilot X ‘off duty and rested’ from the hours of 10:30AM until 9:30PM, and the legal issue is solved. This is unfair to the pilot because he then has to work during his off time (because he had only been scheduled to be on reserve until 10PM). Schedulers have noticed that's what the system does, and they do it now, too .”
On September 11, 2001, airlines faced the most major disruption airlines had ever encountered. The first 737 crew solutions that the CrewSolver system returned rerouted approximately 1,600 pairings. The system solved this problem in less than 17 minutes—a very significant factor in crew recovery for Continental. At that time, the CrewSolver system was designed to load seven days of data -- the current day plus three days in the past and three days in the future -- for the purpose of checking crew time legality. This unprecedented scenario called for loading 14 days of data and solving a time window of 10 days. Designers were able to make modifications so that the system was able to do this, and it put Continental ahead of other airlines in terms of recovery. Continental Airlines estimates that the CrewSolver saved the company $29,289,000. More than half the savings (15 mil) came from avoiding flight cancellations due to crew unavailability. Most of the rest came from avoiding added crew costs (7 mil) and avoiding losses of future revenue from passengers that would have been on unnecessarily canceled or delayed flights (7 mil) and avoiding unnecessary overtime.
Using this system is of great benefit to Continental because a lot of its problems can be formulated quantitatively and can benefit from the organization of such large quantities of information. The human input is very important in selecting the best option, as financial and personal considerations must be kept in mind. Working with the model-driven DSS to solve transportation issues has increased profitability. Because Continental Airlines has such a high information and knowledge load to manage and remain current 24/7, utilization of CrewSolver continues to markedly improved their overall operations. As a DSS, CrewSolver does not make the operational decisions but offers potential solutions. As Professor N. K. Kwak has stated, &quot;Management can make better and more effective judgment by use of mathematical programming. However, it is no substitute for the decision maker's ultimate judgment&quot; (Kwak, as cited in DSS News: Vol. 2, No. 9, 2001, p.2). Lastly, it is worth noting that CrewSolver won the Franz Edelman Award for Achievement in Operations Research and the Management Sciences from the Institute for Operations Research and the Management Sciences ( INFORMS ) in 2002.
Whealan CrewSolver dss
CALEBTECH Crewsolver A Decision Support System (DSS) for Major Airline Crew Recovery Mary Grace Whealan Knowledge Management – Spring 2010
What Is Crewsolver? <ul><li>CrewSolver is part of a product suite of advanced decision support products that provides airlines with powerful solutions to recover from irregular operations and manage their manpower in real-time. </li></ul>
Why Crewsolver? <ul><li>Continental is the 5 th largest US airline, with more than 2,000 daily departures. It serves more U.S. cities than any other airline </li></ul><ul><li>More than 4,000 pilots and 8,000 flight attendants </li></ul>CrewSolver plays an integral role in getting passengers and crew where they need to go in a financially efficient and operationally feasible way.
1993 – Cause for Change <ul><li>In the 1990s, Continental was facing bankruptcy </li></ul><ul><ul><li>Felt change was necessary to make operations run more smoothly </li></ul></ul><ul><li>1993 – “Storm of the Century” </li></ul><ul><ul><li>Continental knew it was time to re-evaluate operations & processes </li></ul></ul>
The Decision-Making Process Actions <ul><li>- Delay Flights </li></ul><ul><li>- Cancel Flights </li></ul><ul><li>- Ferry Aircraft </li></ul><ul><li>- Use Spare Aircraft </li></ul><ul><li>- Swap equipment </li></ul><ul><li>- Swap On-Duty Crew </li></ul><ul><li>Deadhead / Sit Crews* </li></ul><ul><li>- Extend Crew Duty </li></ul><ul><li>Call Out Reserve Crews </li></ul>Operations Manager / Crew Scheduler Challenges ATC* Reduction Inclement Weather Crew* Unavailable Mechanical Grounding Facility Disruptions Open Legs / Pairings* Considerations Aircraft Crew Passengers OpsSolver’s* Scope CrewSolver’s Scope Maintenance http://www.agifors.org/document.go?documentId=1193&action=download
CALEB Technologies Work Together Passenger Customer Notification Passenger Flow Reservation System Revenue Management a Aircraft Fleet Planning Flight Scheduling Fleet Assignment Aircraft Routing Maintenance Inventory Maintenance Manpower Control Scheduling Planning Advanced Integrated Real-time Decision Support Suite (AiRDSS) Crew Manpower Crew Crew Crew Planning Scheduling Assignment Tracking (Pairing) Crew Solver Ops Solver Maint Solver Pass. Solver http://www.agifors.org/document.go?documentId=1193&action=download
What Does CrewSolver Do? <ul><li>ANALYZE PROBLEMS </li></ul><ul><ul><li>Incorporates delays, cancellations, diversions, etc. into a unified framework </li></ul></ul><ul><ul><li>Solves open pairings and legs </li></ul></ul><ul><ul><li>Allows use of reserve crew with cost </li></ul></ul><ul><ul><li>Allows deadheading with penalty </li></ul></ul><ul><li>OFFER SOLUTIONS </li></ul><ul><ul><li>Allows users to set up goals for full recovery of original schedule </li></ul></ul><ul><ul><li>Enforces crew legalities and qualifications </li></ul></ul><ul><ul><li>Partial solutions if no full solution is possible to ensure operations continuity </li></ul></ul><ul><ul><li>Provides alternatives to support users’ decision </li></ul></ul><ul><li>DESIGN & “SOLVE” WHAT-IF SCENARIOS </li></ul><ul><ul><li>Allows users to set multiple objectives for solution procedures </li></ul></ul><ul><ul><li>Facilitates “what-if” analysis to continually improve system design </li></ul></ul>
“ What-Ifs?” & Mintzberg <ul><li>CrewSolver is a combination of Mintzberg’s “ thinking first ,” “ seeing first ,” and “ doing first ” </li></ul><ul><li>The “what-if scenarios” use the “ doing first ” model of enactment selection retention </li></ul><ul><ul><li>This works well because crew recovery deals with continually new and confusing situations; new solutions must always be tried </li></ul></ul><ul><ul><li>Solutions can be implemented in future decision making situations </li></ul></ul>
Cost-Saving Benefits <ul><li>CrewSolver reduces costs in the following ways: </li></ul><ul><li>Guaranteeing crew pay </li></ul><ul><li>Effectively using crews through reserve, deadheading, and layovers if necessary </li></ul><ul><li>Offering solutions that will bring a quicker return to normal operations </li></ul><ul><li>"The benefits go far beyond dollars. The improvement of our operations from passenger & crew perspectives is the most important benefit. It fits seamlessly into our operations & our overall strategy for dealing with disruptions. ...Thanks to these technological advances which take full advantage of operations research, the future for crews & passengers is brighter than before" - Continental Airlines </li></ul>
http://www.agifors.org/document.go?documentId=1193&action=download CrewSolver Solution Approach How Does It Work? Multiple Customized Solutions Summary Statistics Detailed Attribute Lists Legality Checker Solver Engine User Constraints “ What-if” Scenario OpsSolver™ Solution <ul><li>Airline Data </li></ul><ul><li>Crew pairings </li></ul><ul><li>Aircraft routes </li></ul><ul><li>Legality and </li></ul><ul><li>Qualification Data </li></ul><ul><li>Real-time Events </li></ul><ul><li>Cancellations </li></ul><ul><li>Delays </li></ul><ul><li>Diverts </li></ul><ul><li>Scheduled </li></ul><ul><li>Changes </li></ul>
What CrewSolver Looks Like Less than 3 minutes to solve
As a DSS, CrewSolver… <ul><li>Is not an expert system, giving one definitive solution; it gives multiple (3) solutions based on up-to-the-minute system data. Crew schedulers work with this information and their knowledge base to make the ultimate scheduling decisions </li></ul><ul><li>Outlines important factors that must be considered in decision-making process and makes information (crew impact, cost, overall disruption) more quickly accessible </li></ul><ul><li>(Ideally) helps crew managers determine best solution based on both financial and quality-of-life factors </li></ul>
Room for Error <ul><li>The CrewSolver Decision Support System is only as good as the crew scheduler using the system </li></ul><ul><li>The system is dependent upon what information the crew scheduler enters in order to offer possible solutions </li></ul><ul><li>Crew schedulers can ignore “red flags” issued by the DSS and override the system </li></ul>
<ul><li>Using CrewSolver , major disruption took 5 minutes to solve </li></ul><ul><ul><li>Estimated manual solution time: 18 hours </li></ul></ul><ul><li>Fully recovered within 1 day </li></ul><ul><ul><li>Other airlines took up to 3 days to recover </li></ul></ul><ul><li>Crew inconvenience was minimized </li></ul><ul><li>Estimated savings: over $2 Million </li></ul>Recovery Suite in Practice New Year’s Eve 2000 Nor’easter
<ul><li>0 </li></ul><ul><li>10 </li></ul><ul><li>20 </li></ul><ul><li>30 </li></ul><ul><li>40 </li></ul><ul><li>50 </li></ul><ul><li>60 </li></ul><ul><li>9/11 </li></ul><ul><li>9/12 </li></ul><ul><li>9/13 </li></ul><ul><li>9/14 </li></ul><ul><li>9/15 </li></ul><ul><li>9/16 </li></ul><ul><li>9/17 </li></ul><ul><li>9/18 </li></ul><ul><li>9/19 </li></ul>Recovery Suite in Practice September 11 th , 2001 Delays of major airlines Date % Continental Airlines estimates use of the CrewSolver system after the September 11 th attacks saved the company approximately 29 million dollars. For all of 2001 Continental Airlines estimates use of the CrewSolver system saved the company approximately 40 million dollars. Northwest Southwest Delta American Continental
Conclusion <ul><li>"Continental Airlines now reacts to facts , not forecasts . The system's speed allows operations personnel to wait for accurate and complete data before making decisions" (Yu, 2003, p. 18) </li></ul><ul><li>As a DSS, CrewSolver combines system organization of information with human knowledge to facilitate and expedite optimal decisions </li></ul><ul><li>CrewSolver is not a totally perfect system, but it utilizes the technology to its greatest potential </li></ul>
References <ul><li>CALEB Technologies. (n.d.). CALEB CrewSolver System [Brochure]. Retrieved March 5, 2010 from http://www.e-optimization.com/resources/uploads/CrewSolver_for_PDF.pdf </li></ul><ul><li>CALEB Technologies. (n.d.). Optimization power tools for operations planning and recovery [PowerPoint slides]. Retrieved March 5, 2010 from http:// www.agifors.org/document.go?documentId =1221&action=download </li></ul><ul><li>Kabbani, N. and Thengvall, B. (2002). The New CALEB Technologies [PowerPoint slides].Retrieved March 5, 2010 from http://www.agifors.org/document.go?documentId=1193&action=download </li></ul><ul><li>Mintzberg, H. and Westley, F. (2001). Decision making: It’s not what you think. MIT Sloan Management Review, 42(3). 89-93. </li></ul><ul><li>Power, D. J. (2001). Why are transportation problems popular applications for DSS? , DSS News, 2(9). Retrieved March 4, 2010 from http://dssresources.com/newsletters/26.php. </li></ul><ul><li>Ravindran, A. R., Ed. (2008). Operations Research and Management Science Handbook. Boca Raton, FL: CRC Press. </li></ul><ul><li>Yu, G., et. al. (2003). A new era for crew recovery at Continental Airlines. Interfaces , 4(1), 5-22. </li></ul><ul><li>Yu, G. and Xiangtong, Q. (2004). Disruption Management: Framework, Models and Applications . River Edge, NJ: World Scientific Publishing Co., Pte. Ltd. </li></ul>