IE 5511 Human Factors and Work Analysis

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IE 5511 Human Factors and Work Analysis

• Instructor Prof. Caroline C. Hayes
• Fall 2007

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What are Human Factors?

• Human Factors (ergonomics) involves helping
  people to work more efficiently through design of
  their
• Tools (products)
• Work process
• Work environment
• Organizational structure

Where ?
Work environment
Tools (Products)
Work Process
How ?
What ?
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What are Human Factors?

• A collection of disciplines concerned with
  creating effective interactions between people
  and technological systems.
• Examples of disciplines concerned with human
  factors
• Engineering,
• Computer Science
• Psychology
• Business

• Psychology
• Kinesiology, sports
• Medicine,

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Ergonomics (European term for Human Factors)

• Ergonomics comes from the Greek words ergo
  nomos
• Goal of HF is to increase
• Profitability
• Safety/ health/ well being of workers

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Human Factors Body and Mind

• Most products today involve both
• Physical components ? Physical Ergonomics
• Computer component ? Cognitive Ergonomics

• HF involves the design to make human interaction
  in both physical and cognitive aspects effective
  (Such as cell phones, cameras, car (dashboard
  displays))

• Mechanical engineers need to understand both
• May not have HF impact on them
• Need to communicate with HF experts
• Big need Engineers should be able to span
  disciplines/work with other disciplines

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Goals of Human Factors

• To increase humans
• Effectiveness
• Health
• Safety
• Well being

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Goals of the course IE 5511

• To identify
• Human constraints and needs (physical and
  cognitive)
• Approaches for improving productivity, health and
  safety,
• Methods (such as time studies) for assessing a
  product or systems effectiveness,
• The value of standards.

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Who will be teaching you? Course Website
(www.me.umn.edu\education\courses\ie5511)

• Instructor Prof. Hayes
• Email hayes_at_me.umn.edu
• Phone [phone]
• Office ME 2110
• Office Hours Monday, 315 414 pm

• Teaching Assistant Xiao Dong
• Email dongx080_at_me.umn.edu
• Phone
• Office
• Office Hours

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My Background

• Position Professor, Mechanical Engineering,
  University of Minnesota.
• Education PhD, Carnegie Mellon University, 1990
  Robotics
• Appointments Director of Graduate studies for
• Human Factors graduate minor program
• http//www.education.umn.edu/kin/kinesiology
  /HFminor.html
• Research computer supported decision making
• Consulting for local and international firms
  make human/technology systems more efficient and
  effective.

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Expectations

• Homework most weeks, usually due Wednesdays.
• One quiz, two tests, final exam.
• A semester project on a human factors topic,
• Undergrads interested in doing a project, please
  talk to me.

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Grade Breakdowns

• Quiz 10  
• Exams 1 2 40
• Homework 5
• Project 15
• Final Exam 30

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Policies

• Students may discuss homework problems, but they
  are expected to solve problems on their own.
• Make up quizzes and exams will not be given
  except in the case of documented medical
  emergencies.
• Homework is considered late after the end of
  class.
• Late homework will be accepted for 24 hr after
  due date for 50 credit.

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Human Factors Re-engineering Systems
forEfficiency and Safety
Motivation Incentives/rewards
Organizational structure, roles
Work Process
Tools (Products)
Work environment
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Why do Companies Care about Human Factors?

• To make products more competitive and appealing
  to consumers
• Easier to use
• Easier to understand
• Safer
• Higher quality at same or lower cost,

• For a customer, there is always someone else who
  can make
• A more acceptable product
• Better, faster, cheaper

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Why do engineers need to know about Human Factors?

• Because all products are used by people at some
  point in their lifecycle
• Engineers must design these products and process
  by which they are made.

Manufacturing
Engineering
Packaging
Marketing
Product Life Cycle
Delivery
Use
Recycle
Service
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Engineers must design products that

• Fulfill their engineering functions,
• But also
• Can easily be used and understood by people,
• Can be manufactured, assembled, handled by
  people, in all part of their life cycle.
• Are enjoyable to use (Don Norman),

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Examples of Human Factors Needs

• Space Mission planners should be able to control
  the Mars Rover in terms that make sense to them
• Medical Tools Doctors should be able to
  comfortably hold surgical tools without risk of
  dropping it or excessive hand fatigue
• Nuclear power plants operators should be able to
  easily read warnings power plant indicators
• Aviation Pilots should be able to quickly find
  the information they need and intuitively
  understand it

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Examples of HF and Safety

• Nuclear reactor meltdowns
• (Chernobyl, 3 mile Island)
• Melted down largely because
• Although displays showed much of the right
  information,
• Displays were too complex to be understood easily
  by the operator,
• Hundreds of warning bells went off but it was
  hard to know to which to attend.
• Airplane and train accidents
• Farm machinery accidents
• Car accidents cars and cell phones.

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Historical Development

• HF is concerned with the effective interaction of
  people and machines
• Before the industrial revolution people did not
  explicitly worry that much about HF
• Less interaction with machines
• Machines designs were evolved over long time
  periods
• Engineered systems were not as big and
  complicated
• Competition was strictly local

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Historical Development (continued)

• The roots of HF as a science begin in the late
  19th century
• Industrialization increased, and
• Markets expanded from local to national and
  global levels aided by inventions
• Telegraph, telephone, train, steam ships

• Suddenly, businesses needed to be more
• efficient to compete.

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Efficiency Experts

• Fredrick Taylor (start 1881)
• Frank Gilbreth (early 1900)
• Lillian Gilbreth (early 1900)

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Fredrik Taylor, 1881, Midvale Steel, Philadelphia

• Founder of modern time study
• Came up with system of managing work to make it
  more efficient
• Managers plan work 1 day in advance
• Workers get written instructions on tasks and how
  to accomplish them
• Each job has a standard time determined by a
  time study made by experts
• Advocated breaking tasks into elements
• But no one took much notice until 1903 published
  in ASME Shop Management

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Taylor's Studies

• Pig Iron Study (1898)
• At Bethlehem Steel Company
• Established methods for carrying 92 lb. pigs of
  iron up ramp to freight car,
• Provided financial incentives,
• Greatly increased productivity from 12.5
  tons/day/worker to 48 tons (4 fold increase)

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Taylor's Studies (cont.)

• Shoveling Experiment
• Redesigned shovels (were same size for all jobs)
• Short handle for heavy iron
• Long handled scoop for light rice coal
• Results
• Productivity increased
• Material handling costs decreased

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Frank and Lillian Gilbreth(early 20th century)

• Founders of modern motion study techniques
• Study of body motions used in performing tasks
• Aimed at
• Simplifying motions
• Establishing most favorable motion sequences
• As he was in Brick laying trade, Increased
  performance from 120 bricks/hr to 350

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Gilbreths Techniques

• Photographed and Filmed motions to study them
• Cyclographic analysis
• put light on workers finger, and photograph the
  path.
• Chrono-cyclographic analysis
• Put strobe on finger get dotted lines on photo
• Spacing indicates speed
• Devide motion into elements therbligs

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Cyclograph Analysis

• Attach light to finger or part of body,
• Photograph the motion using a long exposure,
• Motion pattern recorded as a line on film.

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Motion photographed in a strobe light
Golfer
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Motion studies using strobe lights
Acrobat pole vaulting
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Motion Study using motion pictures
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Broader Impacts of Effects the Efficiency
Movement

• Efficiency principles were applied in many areas
  outside the factory (turn of the century)
• Architecture Homes were made smaller and layouts
  more efficient with less steps
• Interior design Kitchen workspaces were made
  more efficient (less steps, less reaching, less
  cleaning) Origin of the modern kitchen design.
• Art incorporated motion studies into images
  (Duchamp 1912).

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Nude Decending the Stair, Duchamp 1912
Duchamp (the artist) descending the stair
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Cheaper by the Dozen

• By Gilbreth and Gilbreth, 1948 (children of
  Frank and Lilian)
• Lilian and Frank Gilbreth had 12 children
• They viewed home as efficiency lab
• What will work at home will work in the factory
• Gilbreth shaved with 2 razors (one in each hand)
• Filmed all their children getting their tonsils
  removed.

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Exercise

• Figure out how to fit all the objects in the box
• Decide what actions constitute therbligs or
  elements
• Develop and record a procedure (in terms of
  therbligs)
• Figure out how to do it fast
• Time your procedure (minutes, seconds)
• Did your Therblig description change?
• Did your procedure description change?

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Backlash Against the Efficiency Movement

• Workers some times felt like a cogs in the
  industrial machine,
• When miss-applied, efficiency techniques simply
  squeezed more work out of workers to their
  detrement.
• Workers sometimes refused to cooperate with
  efficiency experts
• Arts and crafts movement in art and architecture
  return to natural forms (hard to make by machine)
  and hand craft methods.

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Charles Chaplin in "Modern Times" 1939
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Current Day Approaches

• Human Factors also focuses also on cognitive
  ergonomics
• Protocol Studies
• Have the person talk out loud as they solve a
  problem
• E.g. create a design or manufacturing plan, or
  solve an algebraic problem
• Record everything said and done on audio and
  video tape, or written notes
• Ethnographic Studies
• Observe in the workplace where people are doing
  tasks
• Nuclear power plant
• Cockpit of airplane
• NASA control center (for Mars Explorations)
• Record what is said and done (video or written
  notes)
• Analyze

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Lessons Learned Designer must consider all of
Motivation Incentives/rewards
Organizational structure
Work Process
Tools (Products)
Work environment
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Methods Engineering

• Technique for
• Increasing production per unit of time.
• Example increasing the number of customers
  that can be handled per cashier by installing bar
  code readers.
• Decreasing cost per unit output.
• Example decreasing total cost of each cell
  phone by reducing the number of parts and thus
  the labor hours required for assembly.
• It is critical to look at impact on whole system.

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Methods Engineering

• Often used synonymously with
• Operation analysis
• Work design
• Corporate re-engineering
• The difference between these terms in the level
  of detail.

Detail level
Big picture level
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Methods Engineering

• Select project
• I.D. product or service experiencing
  difficulties.
• Get and present data
• Study situation, take measurements to
  determine where difficulties really lie,
• Analyze the data
• Figure out which of many problems are most
  critical
• Develop ideal method(s)
• Identify alternative approaches which may
  address most critical problems.

• Present and install method
• at the work site
• Develop a job analysis
• To insure operators are adequately selected,
  trained, rewarded, etc.
• Establish time standards
• Establish fair and equitable standards for
  work performance.
• Follow up the method
• Take measurements to determine if changes
  really did improve situation as predicted.

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Example Mission Planning and control for the
Mars Exploration Rover

• Researchers introduced automated planning tool,
  MAPGEN
• Tool had to fit with users existing way of
  thinking about plans,
• Introduction of new tools caused planning process
  to change,
• Product and processes were evolved together, over
  time.

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Insight

• There is a tight relationship between

The way people actually use a product
Product effectiveness
The features a product ought to have
Customer Satisfaction

• Time and motion studies can help designers
  clarify the relation between products use, and
  the features it ought to have.