Which of the following is a method of improvement United Airlines uses based on customer feedback?

Evaluating performance metrics regularly is a method of improvement used by United Airlines that focuses on continuous enhancement based on data-driven insights. By assessing performance metrics, the airline can track various aspects of its operations, customer service, and overall performance. This data allows them to identify trends, areas for improvement, and customer satisfaction levels. Regular evaluation also enables the company to make informed decisions rather than relying solely on subjective feedback. Implementing changes based on thorough analysis ensures that the modifications are effective and aligned with customer expectations.

Other options may not effectively leverage the collective feedback received. Making gradual adjustments could lead to missed opportunities for significant improvement, while completely changing the service model might introduce unnecessary risks without understanding customer needs. Only addressing the complaints of frequent flyers limits the perspective and does not consider feedback from the broader customer base, potentially missing key areas that require attention.