Boeing Matrix

Human Factors Process for Reducing Maintenance Errors

As a result of the 1997 merger with McDonnell Douglas, the Maintenance Error Decision Aid (MEDA) process offered by Boeing is now available to operators of Douglas-designed commercial airplanes and their maintenance organizations. Since its introduction two years ago, a growing number of maintenance organizations for Boeing-designed airplanes have adopted MEDA, which is a tool for investigating the factors that contribute to maintenance errors. MEDA provides a comprehensive approach for conducting thorough and consistent investigations, determining the factors that lead to an error, and making suggested improvements to reduce the likelihood of future errors.

Maintenance errors cost operators of commercial airplanes millions of dollars each year in rework and lost revenue, and present potential safety concerns. For example, aviation industry studies indicate that as many as 20 percent of all in-flight engine shut downs and up to 50 percent of all engine-related flight delays and cancellations can be traced to maintenance error. In response, Boeing developed the MEDA process to help maintenance organizations identify why these errors occur and how to prevent them in the future. Successful implementation of MEDA requires an understanding of the following:

1. The MEDA philosophy.

2. The MEDA process.

3. Management resolve.

4. Implementing MEDA.

5. The benefits of MEDA.

The MEDA Philosophy

Traditional efforts to investigate errors are often aimed at identifying the employee who made the error. The usual result is that the employee is defensive and is subjected to a combination of disciplinary action and recurrent training (which is actually retraining). Because retraining often adds little or no value to what the employee already knows, it may be ineffective in preventing future errors. In addition, by the time the employee is identified, information about the factors that contributed to the error has been...