Human Systems Integration Course

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SYSTEMS DESIGN APPROACH
J. Robert Bost, Gerald E. Miller J.Robert.Bost_at_nav
y.mil [phone]
Robert J. Beaton, Ph.D., CPE Bob.Beaton_at_navy.mil (
202) 781-2416
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Session Objectives

• After completing this session, you will be able
  to
• Understand HSI systems approach using Big Five
  Questions
• Understand that human behaviors (efficiency
  safety) have relationships to HSI principles
• Recognize importance of physical design
  requirements in design of naval systems

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Session Outline

• Basic HSI Systems Design Approach
• Human Behavior/HSI Relationship
• Physical Design Requirements
• Habitability
• Safety
• Conclusions

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Once Upon a Time

• there was this processing facility
• and there was this conveyor belt that needed
  maintenance
• and there was this employee who did not properly
  lock-out and tag the conveyor
• and there was this arm

Was the accident really the employees fault?
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Examples
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The Big Five Questions

• What is user required to do to operate and
  maintain the equipment?
• Specific tasks (calibrate, repair, remove,
  maintain)
• Body postures required
• Tools or test equipment required

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The Big Five Questions

• What is the users operating environment?
• Temperature
• Air flow/Oxygen content
• Humidity
• Noise, vibration, and acceleration
• Toxic or noxious fumes
• Illumination
• Foot or equipment traffic
• Physical hazards
• Platform movement (vehicles, ships, planes)

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The Big Five Questions

• What is the potential worst case operating
  scenario?
• Trained personnel not available
• Unexpected environmental condition
• Equipment used in an emergency

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The Big Five Questions

• Who is the user?
• Gender (male, female)
• Size (5th to 95th percentile)
• Pre-selected or not screened
• Age/Physical fitness
• Mental abilities

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The Big Five Questions

• What training does the user require?
• Formal training
• Job experience

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Session Outline

• Basic HSI Systems Design Approach
• Human Behavior/HSI Relationship
• Physical Design Requirements
• Habitability
• Safety
• Conclusions

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Efficiency and Safety of Human Behavior

• People are efficient we expend the least energy
  needed to accomplish a task in a perceived safe
  manner
• Equipment designs and procedures can induce
  safety conscious people into committing unsafe
  acts
• Equipment and procedures that do not match our
  cultural expectations eventually result in error

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Efficiency and Safety of Human Behavior

• If procedures or hazard signs are too complex,
  lengthy, or frequent, people tend to avoid
  reading them
• Conversely, if procedures are too simple, people
  ignore them
• If a sign is not readable or incomplete, people
  will guess
• Equipment that is easy to fix tends to work
  better and has higher reliability

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Efficiency and Safety of Human Behavior

• Equipment subject to misuse or poor maintenance
  increases the amount of non-work interaction
  between two or more people
• People judge how a control/display works based on
  the control/display shape, size, and orientation
• Our musculoskeletal system controls the direction
  and amount of manual force applied in completing
  a task

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Session Outline

• Basic HSI Systems Design Approach
• Human Behavior/HSI Relationship
• Physical Design Requirements
• Habitability
• Safety
• Conclusions

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Anthropometrics

• Location and size of equipment should assure easy
  operation and maintenance by personnel in 5th -
  95th percentile or other defined (expected)
  population
• Physical demands on workers should be within the
  following limits
• Minimum overhead height/standing 75
• Minimum height for crawling 31
• Maximum overhead reach 77
• Maximum depth of reach 23

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Walkways/Passageways
Do not put items on either side of bulkheads
within these areas
53-77 IN. (134.6-195.6 cm)
PASSAGEWAY
0-38 IN. (0-96.5 cm)
DECK
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Injury Potential Poor Access or Design

• Valve stems extend into walkway
• Obstructions in walkways and emergency escape
  routes
• Bulkhead mounted equipment
• Low overhead pipes
• Valve handwheels
• Inaccessible valves
• Standing on pipes
• Standing on equipment
• Standing on handrails

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Workplace Crawling Space
Minimum Preferred Arctic Clothes
mm in mm in mm in Q Height 785 31 910 36 965 38
R Length 1500 60 --- --- 1760 70
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Workplace Squatting Space
Minimum Preferred Arctic Clothes
mm in mm in mm in K Height 1220 48 --- --- 1290
51 L Depth 685 27 910 36 --- --- M Height 660 26 1
020 40 1220 44
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Workplace Squatting Space
Minimum Preferred Arctic Clothes
mm in mm in mm in N Depth 1060 42 1220 48 1270 5
0 O Height 1420 56 --- --- 1500 60 P Depth --- ---
685 27 --- ---
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Living Space Habitability Issues
Concern for personnel safety and comfort in
system design.
Color Texture Access Privacy Hygiene Leisure
activities Personal space Comfort

• Lighting
• Noise
• Vibration
• Temperature
• Humidity
• Airflow
• Atmospheric content

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Living Space Habitability Standards

• Updated OPNAVINST 9640.1A
• Increases in berthing clearances
• Vertical berth separation from 18 to 20
• Horizontal separation from 24 to 27
• Maximum of six person cubicles
• Kickout panels for emergency escape from cubicles
• Limit color combinations

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Living Space Past and Present
USS Yorktown, 1943
Today
USS Olympia, 1889
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Living Space Future
Stateroom
Sit-up berth
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Living Space Trends in Habitability Standards

• Affordability Through Commonality (ATC)
• Modular staterooms
• Standard sanitary facilities
• Use of commercial equipment and standards
• Food preparation/serving needs improvement
• Space for physical fitness/exercise
• Access to personal computers for leisure
• Clothing, small stores, accessories available at
  Ships Store

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Injury Potential Poor Access or Design
HATCH

• Inability to access emergency control
• Inability for personnel to operate control with
  gloves
• Inability for personnel to enter confined space
  with PPE
• Poor or missing labeling
• Effects of extreme environments

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Environment Temperature Effect on Performance
TEMP ºF
PERFORMANCE EFFECTS

• Upper limit for continued occupancy over any
  reasonable period of time.
• Expect universal complaints, serious mental and
  psychomotor performance decrement, and physical
  fatigue.
• Maximum for acceptable performance even of
  limited work work output reduced as much as
  40-50, people experience nasal dryness.
• Regular decrement in psychomotor performance
  expected individuals experience difficulty
  falling asleep and remaining asleep.
• Clothed subjects experience physical fatigue,
  become lethargic and sleepy, and feel warm
  unclothed subjects consider this temperature
  optimum without some type of protective cover.
• Preferred for year-round sedentary activity while
  wearing light clothing.

90 80-90 80 78 75 72
NOTE - These temperature effects are based on
relatively still air and normal humidity (40 to
60). Higher temperatures are acceptable if
airflow is increased and humidity is lowered (a
shift from 1 to 4o) lower temperatures are less
acceptable if airflow increases (a shift upward
of 1 to 2o).
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Environment Temperature Effect on Performance
TEMP ºF
PERFORMANCE EFFECTS

• Midpoint for summer comfort optimum for
  demanding visual motor tasks.
• Midpoint for winter comfort (heavier clothing)
  and moderate activity, but slight deterioration
  in kinesthetic response people begin to feel
  cool indoors while performing sedentary
  activities.
• Midpoint for winter comfort (very heavy
  clothing), while performing heavy work or
  vigorous physical activity.
• Lower limit for acceptable motor coordination
  shivering occurs if individual is not extremely
  engaged in continuous physical activity.
• Hand and finger dexterity deteriorates, limb
  stiffness begins to occur, and shivering is
  positive.
• Hand dexterity is reduced by 50, strength is
  materially less, and there is considerable
  shivering.
• Extreme stiffness strength applications
  accompanied by some pain lower limit for more
  than a few minutes.

70 68 66 64 60 55 50
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Environment Noise Effect on Performance
NOISE dB
PERFORMANCE EFFECTS

• Serious reduction in alertness. Attention lapses
  occur. Temporary hearing loss occurs.
• Upper acceptance level for occupied areas.
  Temporary hearing loss often occurs. Speech
  extremely difficult, and people required to
  shout.
• Half of the people judge the environment as being
  too noisy. Some momentary hearing loss occurs.
  Skill errors and mental decrements will be
  frequent. Annoyance factor high, and certain
  physiological changes often occur (for example,
  blood pressure increases).
• Upper acceptance level in range from 150 to 1200
  Hz. Some hearing loss occurs. Considered upper
  comfort level. Some cognitive performance
  decrement can be expected, especially where
  decision making is necessary.
• Conversation is difficult. Difficult to think
  clearly after about 1 hour. May be some stomach
  contraction and an increase in metabolic rate.
  Strong complaints can be expected from those
  exposed to this level in confined spaces.
• Too noisy for adequate telephone conversation.
  A raised voice is required for conversants 2 feet
  apart. Most people judge the environment as too
  noisy.

100 95 90 85 80 75
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Environment Noise Effect on Performance
NOISE dB
PERFORMANCE EFFECTS

• Too noisy for adequate telephone conversation. A
  raised voice is required for conversants 2 feet
  apart. Most people judge the environment as too
  noisy.
• Upper level for normal conversation. Unprotected
  telephone conversation difficult.
• Acceptance level for a generally noisy
  environment. Intermittent personal conversation
  acceptable. Half of the people will experience
  difficulty sleeping.
• Upper limit for spaces used for dining, social
  conversation, and sedentary recreational
  activities.
• Upper acceptance level for quiet spaces. Raised
  voices required to converse over distance greater
  than 8 feet.
• Acceptable to most people where quiet is
  expected. About 25 will be awakened or delayed
  in falling asleep. Normal conversation is
  possible at distances up to 8 feet.
• Very acceptable to all. Recommended upper level
  for quiet living spaces.

75 70 65 60 55 50 40
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Session Outline

• Basic HSI Systems Design Approach
• Human Behavior/HSI Relationship
• Physical Design Requirements
• Habitability
• Safety
• Conclusions

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In this session, you have learned about

• HSI systems approach using Big Five Questions
• Human behaviors (efficiency safety) have
  relationships to HSI principles
• Importance of physical design requirements in
  design of naval systems