HSI Systems Design Approach with Big Five Questions

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

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

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

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?

Examples

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

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)

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

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

The Big Five Questions What training does the user require? • Formal training • Job experience

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

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

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

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”

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

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

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

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 1020 40 1220 44

Workplace: Squatting Space Minimum Preferred Arctic Clothes mm in mm in mm in N Depth 1060 42 1220 48 1270 50 O Height 1420 56 --- --- 1500 60 P Depth --- --- 685 27 --- ---

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

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

Living Space: Past and Present USS Yorktown, 1943 Today USS Olympia, 1889

Living Space: Future Sit-up berth Stateroom

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 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

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).

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

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

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

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

HSI Systems Design Approach with Big Five Questions