HSI 101 1/31/2005 PAGE 1

J. Robert Bost,Gerald E. MillerJ.Robert.Bost@navy.mil(202) 781-2653

SYSTEMS DESIGN APPROACH

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…

Was the accident really the employee’s fault?

• 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 …

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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 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)

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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

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

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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

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”

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53-77 IN.(134.6-195.6 cm)

PASSAGEWAY

0-38 IN.(0-96.5 cm)

DECK

Do not put items on either side of bulkheads within these areas

Walkways/Passageways

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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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mm in mm in mm in

Q Height 785 31 910 36 965 38

R Length 1500 60 --- --- 1760 70

Minimum Preferred Arctic Clothes

Workplace: Crawling Space

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mm in mm in mm in

K Height 1220 48 --- --- 1290 51

L Depth 685 27 910 36 --- ---

M Height 660 26 1020 40 1220 44

Minimum Preferred Arctic Clothes

Workplace: Squatting Space

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mm in mm in mm in

N Depth 1060 42 1220 48 1270 50

O Height 1420 56 --- --- 1500 60

P Depth --- --- 685 27 --- ---

Minimum Preferred Arctic Clothes

Workplace: Squatting Space

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Living Space: Habitability Issues

Lighting

Noise

Vibration

Temperature

Humidity

Airflow

Atmospheric content

Color

Texture

Access

Privacy

Hygiene

Leisure activities

Personal space

Comfort

Concern for personnel safety and comfort in system design.

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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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USS Yorktown, 1943

USS Olympia, 1889

Today

Living Space: Past and Present

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StateroomSit-up berth

Living Space: Future

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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 Ship’s Store

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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

HATCH

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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

Environment: Temperature Effect on PerformanceTEMP ºF PERFORMANCE EFFECTS

*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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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

Environment: Temperature Effect on PerformanceTEMP ºF PERFORMANCE EFFECTS

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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

Environment: Noise Effect on Performance

NOISE dB PERFORMANCE EFFECTS

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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

Environment: Noise Effect on Performance

NOISE dB PERFORMANCE EFFECTS

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