The primary objective of the Practical Application is to develop hands-on skills in event data collection and structured analysis using the MEDA framework.
This practical phase centers on the core of the investigation:
• Interviewing the technician who made the error to uncover the contributing factors and get ideas for process improvement.
Core Guidance and Structured Analysis - The structured nature of MEDA is ensured through the MEDA Results Form, a four-page document used by the investigator during the interview.
Data Collection Tool: The primary tool is the MEDA Results Form, which consists of six sections
• General Information,
• Event,
• Maintenance Error,
• Contributing Factors Checklist,
• Error Prevention Strategies, and
Summar).
Sections I, II, and III establish what happened (the incident).
Section IV establishes why the incident happened (the contributing factors).
Section V covers organizational barriers that failed and recommendations for Error Prevention Strategies.
Structured Interview Process: The interview is the "most important part of the investigation". Key steps for conducting the interview include:
• Gathering information on the error/event beforehand.
• Interviewing people separately if multiple individuals were involved, to prevent influencing accounts.
• Choosing an appropriate, non-threatening, quiet setting.
• Putting the interviewee at ease, maintaining equality, and using a neutral tone to encourage honest feedback.
• Getting the interviewee's un-interrupted version of the event first, then asking specific questions about contributing factors.
• Ending on a positive note by thanking the technician and involving them in suggesting corrective actions (making them part of the improvement process).
Challenges and Overcoming Biases - The practical application of MEDA faces significant human and systemic challenges, which the guide attempts to address through specific instructions and caution against interviewer biases.
Interviewer Biases (Negative Experiences)
The guide highlights several cognitive biases that can negatively affect the investigation's accuracy:
• Attribution Bias: The natural tendency to blame another person's error on their internal factors (e.g., lazy, careless) rather than external contributing factors. The interviewer must overcome this by searching for the "true" contributing factors.
• Experience/Knowledge Bias: Assuming one knows what went wrong before the interview even starts, leading to a closed mind (e.g., "All errors are a result of poor training").
• Proximity Bias: Over-labeling factors close in time or space to the error as causal, potentially missing long-term factors like management staffing decisions.
• Dispositional Blaming: Blaming an error on a person's history or personality instead of the contributing factors for the specific event.
• Practical Challenges & Rules of Causation
The following rules of causation are essential guidance for accurate and actionable analysis, preventing the common pitfalls of vague or incomplete reporting:
Rule 1: Clear Relationship: The connection between the contributing factor and the error must be clearly written down in the Results Form.
Rule 2: Avoid Negative Descriptors: Do not use vague terms like "poorly" or "inadequate." Specificity is needed to propose corrective action (e.g., explaining precisely why the manual was "poorly" written).
Rule 3: Preceding Factor for Deviation: Every procedural deviation (e.g., failure to use the manual, skipping a check) must have a preceding contributing factor (the reason why the deviation occurred). The "ask why five times" rule-of-thumb helps trace the causal chain to the correct level for corrective action.
Rule 4: Duty to Act: A failure to act (an omission) is only a contributing factor when there is a pre-existing duty to act (a required policy or procedure).
Best Practices Considerations - Best practices for the application of MEDA usually emphasize a systemic, non-punitive, and continuous improvement approach.
• Non-Punitive Philosophy (Positive Experience): The fundamental philosophy is that errors are not made on purpose but result from contributing factors in the workplace. The belief is that anyone confronted with the same contributing factors might make the same error. This philosophy is key to gaining the technician's trust and honest data.
• Focus on Management Control: An estimated 80%–90% of contributing factors are under management control. This empirical data reinforces the need to focus on systemic issues (policies, procedures, environment) rather than personal shortcomings.
• Multifactorial Causation (Empirical Data): Field tests of MEDA showed that errors typically do not result from a single factor; there were, on average, about four contributing factors to each error. Investigators must probe deeply to find this "series of contributing factors".
• Systemic View: The maintenance organization must be viewed as a socio-technical system where the technician is just one part, operating within an immediate environment and under supervision, all guided by the organization's philosophy.
• Value of Low-Level Events: Data showed that contributing factors to low-cost/no-injury events were the same as those for high-cost/personal-injury events. This is empirical data supporting the practice of addressing the contributing factors for all errors to prevent more serious events.
• Feedback Loop: A crucial final step is to provide feedback to employees on what process improvements are being made, which reinforces that the MEDA process is for improvement, not punishment.
Sofema Aviation Services and Sofema Online delivers Maintenance Error Management System (MEMS) and Maintenance Event Decision Aid (MEDA) training as Classroom, Webinar and Online training, For details please see the websites or email team@sassofia.com
