1. HRA: Aerospace Challenges
Including Human Reliability In Considerations for Risk
Diana DeMott – SAIC

2. What is HRA? Human Reliability Assessment (HRA)
The human in the loop directly causes a failure or accident
The human does something to make a failure worse
The human fails to correct the problem

3. Types of Human Actions (that can contribute to failures)
Direct actions (push the button, switch)
Monitor (verify information or programmed activities)
Support (provide information which influences direct action)
Evaluate (cognitive process to determine the course of action to be taken)
Errors of omission versus commission
Test and maintenance errors
Procedural errors (not following or skipping steps)
Errors leading to inappropriate actions
Recovery errors

4. Why Use HRA?
Identify how human actions (or inactions) affect accidents or failures
Identify human-in-the-loop contribution to reduce the risk
Complete the risk picture
Performed during the design phase, HRA can highlight human interfaces and postulated failures and influence design (Risk Informed Decision Making)
Determine if the risk can be mitigated by modifying the design
Feedback to system design, Human Factor Engineers, operations procedures, and simulator training scenario development
Design redundancy issues could use the HRA assessments for cost / benefit trade studies
Comparison of competing designs
Prioritization of design considerations

5. HRA Challenges Individual Human Action Being Assessed
End User of HRA Results
Perception
Accused of not performing job properly
Machines are more reliable than people
Results
What actions are most important based on risk
Where to concentrate efforts for reducing risk
Understanding
What can be done to eliminate or mitigate human errors
People are part of any process with advantages and disadvantages
Results
Understanding

6. Examples of Human Reliability
Pilot preparing for take-off – actions important for the safety of all
Passengers – actions important for individual safety

7. Conclusion
HRA is another tool that can be used to improve designs and/or operations to reduce overall risk and provide information for Risk Informed Decision Making
When using a tool:
Know what the tool can do for you
Use the right tool for the job
Know how to use the tool effectively