Bob Jordan, the company's chief executive, was happy after Southwest Airlines made it through Thanksgiving. He said the company's performance had been "just incredible" at a meeting with analysts and investors.

Southwest had to cancel a lot of flights over the Christmas holiday due to their operations going into paralysis. The debacle has raised questions about Mr. Jordan's performance and prompted employees and analysts to ask why the company has been slow to fix known weaknesses.

Southwest canceled more flights on Wednesday than any other airline in the US, but other airlines did a better job. More than 2,300 of the airline's flights have been canceled.

People are demanding answers from Southwest and Mr. Jordan. The company has apologized for its performance many times, but has not provided any details about how it went wrong or what it is doing to correct it. Mr. Jordan and other executives were not available for an interview.

Mr. Jordan implied on Tuesday that the airline was caught out by a low-probability event after many delays and cancellations.Credit...Christopher Goodney/Bloomberg

Mr. Jordan implied in the video that Southwest was caught out by a rare event. The tools we use to recover from disruption serve us well 99% of the time, but we need to double down on our already existing plans to upgrade systems for these extreme circumstances.

Southwest has known for a long time that the computer systems that assign pilots and flight attendants needed to be improved. When the company's operations are disrupted, the systems struggle to handle large numbers of changes.

Southwest uses a point-to-point system in which planes travel from one destination to another, and other large airlines use the hub-and-spoke system.

Southwest said in an email to the New York Times that it was trying to piece together its operations after many of its crews and planes were not where they were supposed to be. The effort is expected to take days because the company's operations have been completely upended. Southwest had to reduce its schedule in order to get crews and planes where they need to be. The airlines should be able to bring crews to airports where they're needed.

Southwest's model was vulnerable to breaking down under stress, according to Mr. Jordan in his video. The operation of the airline is dependent on aircraft and crews remaining in motion to their destinations.

Many travelers have expressed frustration with Southwest, saying it has become impossible to get information from the company.Credit...Emil Lippe for The New York Times

The company has spent years trying to update its technology systems, but this latest crisis is expected to increase the pressure on Southwest and Mr. Jordan.

The union leaders said they had run out of patience with the company.

Michael Santoro, vice president of the Southwest Airlines Pilots Association, said in an interview that they had given Mr. Jordan enough grace.

The Transport Workers Union Local 556 agreed with the pilots. It is not weather, it is not staffing, it is not a concerted labor effort, and it is the complete failure of Southwest Airlines executives. The president of the union said that it was their decision to continue to expand and grow.

Southwest has a good relationship with most of its unions. The company has become more critical of itself this week. The pilots group was frustrated that the company hadn't shared its plan for getting its operation back to normal. Mr. Santoro said they had heard nothing.

Southwest Airlines staff members helped customers at Dallas Love Field Airport on Tuesday.Credit...Emil Lippe for The New York Times

In the last few days, union officials, pilots and flight attendants have complained to journalists and on social media that they have had to wait hours to be assigned to their next flight or be directed to hotels where they could spend the night.

Customers said it was impossible to get any information from the company. People have said they waited in line for hours to speak to Southwest agents. People have tried and failed to get through to the company.

Howard Tutt went to Chicago's Midway airport on Wednesday to try to get his son's bag back after it was canceled. He said he had been waiting for someone to speak to him. Dozens of bags were waiting to be picked up by travelers outside Southwest's baggage office.

Mr Tutt said that his son had to leave in the middle of Christmas dinner because he couldn't get on a flight. He was stuck at the airport for six hours before the flight was canceled.

Mr. Tutt said the family had tried a number of approaches to locate the bag, which contained Christmas gifts for his son's girlfriend and her family. We have tried and failed to reach anyone.

Southwest needed to start from scratch to rebuild after it found itself in a dire position due to the number of canceled flights. The senior vice president and airline industry analyst at the consulting firm said that you have lost control of what you expected.

The question that will loom over the company for a long time is why Southwest broke down while other airlines did not. Southwest has a point-to-point network that makes it harder to restart operations.

Despite years of modernization, Southwest's technology was lacking. Southwest has had to deal with weather and technology disruptions in the past and Mr. Jordan is likely to be asked why he didn't do more.

Mr. Jordan has been a member of Southwest's senior leadership team for many years, which would have given him a better idea of the company's strengths and weaknesses. After Southwest acquired AirTran Airways, he helped incorporate the planes and crews of that company into the frequent fliers program.

Robert W. Mann said that Mr. Jordan was in the hot seat.

Analysts weren't sure if Southwest could change quickly. Southwest exceptionalism is what they say the company's management suffers from. Southwest has been seen as an upstart taking on sleepy incumbents, but analysts say its decision making can take a long time.

The airline has always been careful about change.

Southwest has had a strong financial performance over the last 50 years because of its approach, according to analysts. It made it possible for planes to be used more quickly. Longtimers have done well. Southwest's stock is up 217 percent over the last 10 years, more than any other company. Southwest's stock has fallen more than the market and its peers.

There isn't any evidence that Mr. Jordan is at risk. Poor crisis management has hurt other airline executives.

When an ice storm on the East Coast caused air travel to be disrupted, the airline did not act as quickly as it should have. Nine planes filled with passengers sat on the tarmac at Kennedy for six hours.

David G. Neeleman said he was embarrassed and humiliated at the time. He stepped down as CEO months later.

Mr. Neeleman didn't reply to questions.

Robert was a contributor.