HSI 101 1/31/2005 PAGE 1
SYSTEMS
DESIGN
APPROACH
J. Robert Bost,
Gerald E. Miller
J.Robert.Bost@navy.mil
(202) 781-2653
Robert J. Beaton, Ph.D., CPE
Bob.Beaton@navy.mil
(202) 781-2416
HSI 101 1/31/2005 PAGE 2
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
HSI 101 1/31/2005 PAGE 3
Session Outline
Basic HSI Systems Design Approach
Human Behavior/HSI Relationship
Physical Design Requirements
• Habitability
• Safety
Conclusions
HSI 101 1/31/2005 PAGE 4
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 employee’s fault?
HSI 101 1/31/2005 PAGE 5
Examples
HSI 101 1/31/2005 PAGE 6
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
HSI 101 1/31/2005 PAGE 7
The Big Five Questions
What is the user’s 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)
HSI 101 1/31/2005 PAGE 8
The Big Five Questions
What is the potential worst case operating scenario?
• Trained personnel not available
• Unexpected environmental condition
• Equipment used in an emergency
HSI 101 1/31/2005 PAGE 9
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
HSI 101 1/31/2005 PAGE 10
The Big Five Questions
What training does the user require?
• Formal training
• Job experience
HSI 101 1/31/2005 PAGE 11
Session Outline
Basic HSI Systems Design Approach
Human Behavior/HSI Relationship
Physical Design Requirements
• Habitability
• Safety
Conclusions
HSI 101 1/31/2005 PAGE 12
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
HSI 101 1/31/2005 PAGE 13
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
HSI 101 1/31/2005 PAGE 14
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
HSI 101 1/31/2005 PAGE 15
Session Outline
Basic HSI Systems Design Approach
Human Behavior/HSI Relationship
Physical Design Requirements
• Habitability
• Safety
Conclusions
HSI 101 1/31/2005 PAGE 16
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”
HSI 101 1/31/2005 PAGE 17
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
HSI 101 1/31/2005 PAGE 18
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
HSI 101 1/31/2005 PAGE 19
Workplace: Crawling Space
Minimum
mm in
Preferred
mm in
Arctic Clothes
mm in
Q
Height
785
31
910
36
965
38
R
Length
1500
60
---
---
1760
70
HSI 101 1/31/2005 PAGE 20
Workplace: Squatting Space
Minimum
mm in
Preferred
mm in
Arctic Clothes
mm in
K
Height
1220
48
---
---
1290
51
L
Depth
685
27
910
36
---
---
M
Height
660
26
1020
40
1220
44
HSI 101 1/31/2005 PAGE 21
Workplace: Squatting Space
Minimum
mm in
Preferred
mm in
Arctic Clothes
mm in
N
Depth
1060
42
1220
48
1270
50
O
Height
1420
56
---
---
1500
60
P
Depth
---
---
685
27
---
---
HSI 101 1/31/2005 PAGE 22
Living Space: Habitability Issues
Concern for personnel safety and comfort in system
design.
Lighting
Noise
Vibration
Temperature
Humidity
Airflow
Atmospheric content
Color
Texture
Access
Privacy
Hygiene
Leisure activities
Personal space
Comfort
HSI 101 1/31/2005 PAGE 23
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
HSI 101 1/31/2005 PAGE 24
Living Space: Past and Present
USS Yorktown, 1943
Today
USS Olympia, 1889
HSI 101 1/31/2005 PAGE 25
Living Space: Future
Sit-up berth
Stateroom
HSI 101 1/31/2005 PAGE 26
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 Ship’s Store
HATCH
HSI 101 1/31/2005 PAGE 27
Injury Potential: Poor Access or Design
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
HSI 101 1/31/2005 PAGE 28
Environment: Temperature Effect on Performance
TEMP ºF
PERFORMANCE EFFECTS
90
Upper limit for continued occupancy over any reasonable period of time.
80-90
Expect universal complaints, serious mental and psychomotor performance
decrement, and physical fatigue.
80
Maximum for acceptable performance even of limited work; work output
reduced as much as 40-50%, people experience nasal dryness.
78
Regular decrement in psychomotor performance expected; individuals
experience difficulty falling asleep and remaining asleep.
75
Clothed subjects experience physical fatigue, become lethargic and sleepy,
and feel warm; unclothed subjects consider this temperature optimum
without some type of protective cover.
72
Preferred for year-round sedentary activity while wearing light clothing.
*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 2 o).
HSI 101 1/31/2005 PAGE 29
Environment: Temperature Effect on Performance
TEMP ºF
PERFORMANCE EFFECTS
70
Midpoint for summer comfort; optimum for demanding visual motor tasks.
68
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.
66
Midpoint for winter comfort (very heavy clothing), while performing heavy
work or vigorous physical activity.
64
Lower limit for acceptable motor coordination; shivering occurs if
individual is not extremely engaged in continuous physical activity.
60
Hand and finger dexterity deteriorates, limb stiffness begins to occur, and
shivering is positive.
55
Hand dexterity is reduced by 50%, strength is materially less, and there is
considerable shivering.
50
Extreme stiffness; strength applications accompanied by some pain; lower
limit for more than a few minutes.
HSI 101 1/31/2005 PAGE 30
Environment: Noise Effect on Performance
NOISE dB
PERFORMANCE EFFECTS
100
Serious reduction in alertness. Attention lapses occur. Temporary hearing loss
occurs.
95
90
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).
85
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.
80
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.
75
Too noisy for adequate telephone conversation. A raised voice is required for
conversants 2 feet apart. Most people judge the environment as too noisy.
HSI 101 1/31/2005 PAGE 31
Environment: Noise Effect on Performance
NOISE dB
PERFORMANCE EFFECTS
75
Too noisy for adequate telephone conversation. A raised voice is required for
conversants 2 feet apart. Most people judge the environment as too noisy.
70
Upper level for normal conversation. Unprotected telephone conversation
difficult.
65
Acceptance level for a generally noisy environment. Intermittent personal
conversation acceptable. Half of the people will experience difficulty sleeping.
60
Upper limit for spaces used for dining, social conversation, and sedentary
recreational activities.
55
Upper acceptance level for quiet spaces. Raised voices required to converse over
distance greater than 8 feet.
50
40
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.
HSI 101 1/31/2005 PAGE 32
Session Outline
Basic HSI Systems Design Approach
Human Behavior/HSI Relationship
Physical Design Requirements
• Habitability
• Safety
Conclusions
HSI 101 1/31/2005 PAGE 33
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