IE 590D Applied Ergonomics

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IE 590D Applied Ergonomics

• Lecture 26 Ergonomics in Manufacturing
  Automation
• Vincent G. Duffy
• Associate Prof.
• School of IE and ABE
• Thursday April 13, 2006

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IE 486 Work Analysis Design II
Instructor Vincent Duffy, Ph.D. Associate
Prof. Lecture 19 Automation in Work
Design Thurs. April 5, 2007
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Automation - Chapter 16 in Wickens, et al.

• Initial example China Airlines
• automation did such a good job initially that
  pilots were unaware of the problem .failing
  engine
• danger of automation on long flights, flight
  crew can be lulled into complacency or
  calm/slow to recognize the need to respond
• sometimes automation is trusted more than it
  should be

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QOTD

• Address the similarities in discussion about
  automation and decision making.
• Why automate?
• Briefly describe different levels of automation
• What are some potential problems in automated
  systems?
• Briefly discuss automation in complex systems.
• How should one manage failure of automation?
• What is the goal of automation?
• What are characteristics of human-centered
  automation?

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Similarities between discussion about automation
and decision-making

• Note that in the discussions about automation
  they talk a lot about decision making.
• Essentially what you see is that automation has
  some impact on how decisions are made
• so you see references to Rasmussen and
  discussions about how automation can SUPPORT
  perception, cognition and control

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Automation decision making

• Perception one challenge is to make sure
  appropriate/reliable sensitivity so as to not
  cause loss of trust
• ground proximity warning systems in aircraft
• Cognition decision making is considered more
  complex than perception
• so is the development of automated devices to
  replace or assist in functions related to
• intelligent reasoning
• Control
• sensing position and trend cruise control in
  driving controls pedal, but steering is still
  manual

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Why automate?

• 1. Either dangerous or impossible for humans to
  perform the equivalent task
• 2. Humans may carry out the task poorly
• examples include fatigue on long flights,
• humans not good at vigilant monitoring
• 3. To aid the human in doing things
• recall the human memory is vulnerable to
  forgetting
• 4. Because the technology is available and
  inexpensive
• eg. A computer operator may be less expensive
  over time.

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Stages and levels of automation
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Problems in automation

• 1. It may be unreliable
• key parts may fail
• 2. Human operator may make an error in use
• Korean air - shot down over Soviet airspace
• pilots misprogrammed the navigation system
• dumb and dutiful
• 3. Does what it should, but APPEARS to be in
  error
• eg. Sudden shift in air speed or altitude
• then operator may make inappropriate intervention

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Automation in complex systems

• Combinations of lags and complexity plus
  hazardous processes leads to increased need for
  automation in some cases
• when things go wrong eg. Three mile island,
  Bhopal, Chernobyl
• It is important to keep the operator involved
  while monitoring the automation
• high situation awareness
• how to do this when there is little to do?
• An important challenge for the designer

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Managing failure

• 1. Ensure safety
• 2. Minimize damage to the plant
• 3. Identify the nature of the fault -diagnosis
• too much concern for one or the other may cause
  additional problems
• balance is needed - by the manager
• it is important to keep in mind that good
  displays can help in diagnosis
• information should be presented in a way that is
  consistent with the operators mental model of
  the plant

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• Use of integrated displays may help the manager
  understand the relationships between key plant
  variables
• example nuclear accident
• display showed that signal was given to close a
  valve.
• However, the valve was stuck open and the
  understanding of the current status of system
  cooling was improperly understood by decision
  makers

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Goal

• Keep the human in touch with the automated
  process
• give more authority to the human over automation
• choose a level of involvement for the human that
  leads to maximum performance
• and creates maximum satisfaction
• These may not all be compatible!
• Especially when we consider that a human out of
  the loop for some time may lose skills!

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Human-centered automation

• Wickens suggests
• Keep the human informed
• with good displays
• keep the human trained
• so long as there is the possibility that they may
  go to manual operations
• keep the operator in the loop
• maintain situation awareness without giving back
  the gains of automation (without reverting
  totally to manual control)
• make the automation flexible and adaptive
• flexible - one operator chooses control, the
  other not
• adaptive - the level of automation may change by
  condition

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Trust

• Inefficiency or ineffectiveness can lead to
  mis-trust -lack of trust
• if too much trust - good automation, then
• poor detection - rare signal events may be missed
  - and poorer detection over time
• poor situation awareness - many times SA is
  better if they monitor a system than perform the
  task manually
• however, they are less likely to intervene if
  they dont have confidence or dont think they
  understand how the system really works
• skill loss - can occur without participation in
  decisions over time