SY DE 142 Final Exam Review

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SY DE 142Final Exam Review

• Roshanak Moradi
• Munira Jessa
• August 12th , 2004
• Introduction to Human Systems Engineering
• Waterloo, Ontario, Canada

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Outline

• Exam Details
• Case Studies
• Course Material

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Exam Details

• Friday August 13, 2004 from 900 to 1200
• E2-1303 A,B, and E (NOT the regular classroom)
• Aids Allowed
• Set Phasers on Stun,
• Wickens,
• basic calculator (not programmable)
• Format
• Short answer questions (from case studies)
• Crossword puzzle
• Anthropometric/Biomechanical questions
• Case study (same as practice final)

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Some pointers on exam preparation

• Final From Last year/s -? get a sense of how
  things went
• No Multiple Choice this year, you got a puzzle
• we find students know the material in a general
  sense, but make errors in terms of expressing
  things clearly, hitting all the points, thinking
  hard about the question and really taking the
  right approach etc. 
• prepare by working through the web assignments. 
  
• Try the case study from 3mile island and look at
  solutions.
• Critique your solution presentation and develop
  a perspective on exam writing
• Try to communicate with marker, be thoughtful and
  thorough. 
• Watch the marks allowed on all questions.  They
  are a strong indicator for the number of points
  expected. 

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Case Studies

• Business in Bhopal
• Silent Warning
• In Search of the Lost Cord
• An Act of God
• The Wizards of Wall Street

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More Case Studies

• Rental Car
• Set Phasers on Stun
• Zzzzs in Zeebrugge
• The Peppermint Twist
• Never Cry Wolf
• Tigershark!
• Return from Salyut
• Genie in a Bottle

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1st half

• Accident Analysis and Fault Trees
• Mappings and Affordances
• Gulfs of Execution and Evaluation
• Human Action Cycle
• Information Processing
• Human Decision Making
• Human Error - Mistakes

• Human Error- slips
• Human machine model
• Displays
• Control
• Human-Computer Interaction
• Usability Testing
• Automation

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2nd half

• Usability Testing
• Stress and mental workload
• Circadian Rhythms/Shift work
• Vision
• Lighting Visual Search
• Noise and Vibration
• Indoor Climate

• Anthropometry
• Work Physiology
• Biomechanics
• Social Factors, Teamwork
• Transportation
• Personnel / Training

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Some notes on FTA

• Faulty policies are definitely factors in
  accidents. A fault tree analysis is nothing more
  than a chain of events though. Things which are
  overall factors are not included e.g." worker was
  tired/stressed/not trained". These are not
  events.
• The FTA looks at events with the object. If the
  user initiates an event then it can go in the
  analysis. The description though must be event
  based e.g. "machine in high radiation mode" and
  "activation button pressed." Note that this
  describes the state and the events of the object.

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Usability and user testing

• Usability Approaches (4)
• Cognitive walkthrough
• Heuristic evaluation (Neilsons usability
  principals)
• Performance measurement
• Field study
• Tasks
• Usability measures (satisfaction, learnability,
  errors)

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Design for user

• User health and safety
• Circadian Rhythms and Shiftwork
• Vision
• Health related environmental issues
• Lighting
• Noise and Vibration
• Indoor climate

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Design for Groups

• Group characteristics
• Groupthink
• Social Factors, Teamwork and Communication

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Stress and Mental Workload

• Yerkes-Dodson Law

• Measurement
• Primary Task
• Speed, Accuracy
• Secondary Task
• Add a 2nd task and measure it
• Physiological
• Heart Rate, Blood Pressure
• Subjective
• Questionnaires

• Optimum Level of Arousal

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Visual Search

• Identification of targets in a field of
  non-targets (distractors)
• Time (1 target) (number of items x inspection
  time)/2
• Average time, based on probability of finding a
  target
• Key points more itemsmore time
• Only applies to very itemized searches (e.g.phone
  books)

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Vision Lighting Indoor Climate

• Visual system , Visual Fatigue
• Ergonomics of visual tasks
• Intensity measurement with their units.
• (Luminous Flux from source), Illumination on
  surface, Luminance from surface)
• Reflectance Luminance (FL)/Illuminance (FC)
• Types of lighting in accordance to workspace
  (notes)
• Climate and air quality rules and guidelines (see
  notes)

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Anthropometrics

• Design
• Determine who the users are (the population)
• Determine the relevant body dimensions
• Determine the relevant percentage level
• Both male and female?
• Is 5th-95th range too small?
• Do you need both ends of the range for that
  problem?
• Dont just use 50th percentile

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Anthropometrics

• Work Space Design
• Clearances must accommodate the largest users
• Reach envelopes must consider minimum reach
• Visibility most comfortable visibility range
• Work surface height 5-10 cm below elbow height
  (higher for precise work, lower for work
  requiring force)

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Link Analysis

• Technique for determining arrangement
• Spatially organize components
• Link by variable of interest
• travel time
• frequency of use
• Thickness of link represents variable
• Redesign to improve variable of interest

B
C
P
M
C
P
B
M
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Work Physiology

• Muscle Structure
• Aerobic vs Anaerobic Activity
• Muscle Efficiency 20
• Heart Parameters
• Cardiac Output
• Heart Rate
• Stroke Volume

• Basal metabolic rate 1600-1800 kcal/day
• Short Term (Aerobic) Work Capacity
• about 15kcal/min men
• 10 kcal/min women
• Long Term Work Capacity
• suggested not over 1/3 of short term for 8 hrs
• Designed Rest Schedules

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Biomechanics of Work

• Statics model (åF0, åMoments0), isometric
  contraction
• L5/S1 Lumbosacral Disc (p.329)
• Cumulative Trauma Disorders (CTDs)
• Fingers, hand/wrist, elbow, shoulder
• tendon irritation
• muscle loading due to unnatural postures
• blood obstruction

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NIOSH Lifting Equation

• RWL LC x HM x VM x DM x AM x FM x CM
• LC load constant, maximum recommended weight
• HM horizontal multiplier, decreases weight with
  distance from spine
• VM vertical multiplier, lifting from near floor
  harder
• DM distance multiplier, accommodates for
  vertical distance that must be lifted
• AM asymmetric multiplier, reductions for torso
  twisting
• CM coupling modifier, depends on whether loads
  have handles for lifting
• FM frequency modifier, how frequently is the
  load lifted
• Multipliers can all be obtained from tables
  (11.1, 10.2, 10.3, 11.2, 11.3)

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More

• Transportation
• Tasks in driving
• Distractions and issues
• some causal factors to accidents
• Personnel selection
• Methods
• Resume and Interview.
• Behavioral interview
• Various tests