Human Failure Modes

Copyright © 2012 Azad Madni

Human Failure Modes

Dr. Azad M. MadniProfessor , Epstein Department of Industrial and Systems Engineering

Director, SAE ProgramCo-Director, CSSE

March 6, 2012


Outline

■ Human Failure Modes■ Demanding Systems Requirements■ Implications for Humans■ Evolving Human Roles■ Systems Engineering Mindset ■ The Remarkable Human Brain■ Human Error Sources■ Potential Remedies and Opportunities


Human Failure

■Comprises human errors, which are unintentional behaviors violations, which are willful disregard of rules and

regulations■Human errors fall into specific categories

slips, lapses of memorymistakes in following rules and proceduresmistakes in understanding


Demanding System Requirements

■ Adaptability■ Reconfigurability■ Composability■ Resilience

These requirements pose formidable challenges for humans that work with and within complex

systems


Implications for Humans

■System adaptability implies changing contexts and potential changes to human-system interactions

■System reconfigurability implies potential changes to human roles and human-system function allocation

■System resilience implies potential dynamic changes to human role and attendant changes to cognitive load

■System composability (as in SoSs) implies potential changes in collaborators (lack of shared conceptual model)These changes can increase likelihood of human

error.


Evolving Human Roles

■From that of operator outside system to that of agent within an adaptable system

decision maker supervisor monitor with override

authority re-assignable participant

(peer, assistant)These roles require new behaviors.


Systems Engineering Mindset

• Humans are suboptimal job performers that need to be shored up and compensated for during task performance

• This perception leads to systems that are inherently incompatible with human conceptualization of work

• The resulting mismatch inevitability creates human reliability issues that show up as human error

This mindset fails to capitalize on human ingenuity


The Remarkable Human Brain

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ltteers in a wrod aepapr, the olny iprmoatnt tihng is taht the frist and lsat ltteer are in the rghit pcale. The rset can be a toatl mses and you can sitll raed it wouthit pobelrm.

■ S1M1L4RLY, Y0UR M1ND 15 R34D1NG 7H15 4U70M471C4LLY W17H0U7 3V3N 7H1NK1NG 4B0U7 17.

■ How ?

Source: LiveScience.com


Human Error Sources (Examples) ■ Erroneous/Incomplete Mental Model

often traceable to poor design- results in mistakes lack of complete info causes user to make

unwarranted assumptions about system state also results from misrecognition of cues/state info

■ Drop in Vigilance/Arousal during Monitoring occurs with infrequent stimulus leading to

missed cue detection ■ Loss of Focus during Task Performance

results in slips (execution errors) arising from inattention ■ Cognitive Overload

causes: multi-tasking, context switching, decision making under stress

can lead to suboptimal behaviors and human errors (mistakes and slips)


Key Findings

■ Humans change cognitive strategies under overload ■ Inverted-U relationship: performance & stress■ Humans unable to distribute attention under stress■ Adaptability of human-in-the-loop system is

upper-bounded by acceptable human error rate■ System inspectability facilitates human intervention

and avoids having to make erroneous assumptions■ For robust performance

need to minimize multitasking and context switching employ alerting/automation to monitor and flag rare events need to understand cognitive strategies under overload for effective aiding


Potential Remedies

■ Design human work to avoid multi-tasking and frequent context switching to the extent possible

■ Assign rare event monitoring to automation or alerting mechanisms

■ Provide decision aiding and performance support for decision making under stress

■ Design appropriate incentives to counter risk compensation tendency

■ Employ automation and dynamic function allocation to assure manageable cognitive loadMost complex problems will require a combination

of many of these remedies.


Potential Opportunities

■ Exploit human ingenuity and creativity in:adapting to shifting contextsgeneralizing from specificsrecognizing novelty and improvisingaggregating information in the absence of an algorithmdetecting and filling gaps (e.g., in narratives)

Most complex problems will require a combination of human creativity and ingenuity.


So,….Is Human Error a Cause or Consequence?

Thank You


My References

■ Madni, A.M. “Integrating Humans with Software and Systems: Technical Challenges and a Research Agenda,” Keynote Presentation, 22nd Annual Systems & Software Technology Council, Salt Lake City, Utah, April 26–29, 2010.

■ Madni, A.M. “Integrating Humans with Software and Systems: Technical Challenges and a Research Agenda,” INCOSE Journal of Systems Engineering and, Vol. 13, No. 3, 2010.

■ Madni, A.M. “Integrating Humans with Software and Systems: Technical Challenges and a Research Agenda,” Keynote Presentation, INCOSE 2010 LA Mini-Conference, Loyola Marymount University, October 16, 2010.

■ Madni, A.M. “Integrating Humans With and Within Software and Systems: Challenges and Opportunities,” (Invited Paper) CrossTalk, The Journal of Defense Software Engineering, May/June 2011, “People Solutions.”

Documents

Human Failure Modes