CrewSolver is a decision support system created by CALEB Technologies to help major airlines like Continental Airlines manage irregular operations and crew scheduling. It provides solutions to issues like delays, cancellations and crew unavailability. CrewSolver analyzes problems, offers multiple optimized solutions that consider goals, costs and crew legality, and allows schedulers to evaluate "what if" scenarios. Use of CrewSolver saved Continental an estimated $40 million in costs in 2001 by quickly recovering from disruptions like 9/11.
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 "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 "crew" 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 "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, "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" (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.