Human-Centered Systems Engineering: Human Factors Engineering

from Lust to Dust

LECTURE 4: HFE Contributions

GM Samaras, PhD, DSc, PE, CPE, CQE Samaras & Associates, Inc., Pueblo CO USA www. samaras-assoc.com george@samaras.eng.pro

Today’s Agenda

MORNING • 8:45 – 9:30

Introduction to HCSE • 9:30 – 10:15

Group Exercise • 10:15 – 11:00

HCSE Lifecycle Elements • 11:00 – 11:45

Exercise continued • 11:45 – 12:30

Complexity & NWDs

AFTERNOON • 13:45 – 14:30

HFE Contributions • 14:30 – 15:15

Exercise continued • 15:15 – 16:15

Experimental Design • 16:15 – 17:00

Exercise continued • 17:00 – 17:30

Innovation & Regulation

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THE FACTORS OF HUMAN FACTORS What are HF Factors and how to Measure them

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All this “stuff” not very useful, if you cannot measure it!

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Why Metrology ???

• You cannot manage what you cannot control • You cannot control what you cannot measure

ALSO • You cannot measure what you cannot define • You cannot define what you do not know about

– so be skeptical & curious

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OVERT ≡ Can detect with one or more of 5 senses COVERT ≡ Cannot detect with any of 5 senses

“Overt/Covert” are NOT psycho-mumbo-jumbo or spy stuff! PHYSICS EXAMPLE (free body problem):

Acceleration (a covert quantity) is proportional to the second time derivative of displacement (an overt quantity)

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Physical Measurements • OVERT Phenomena

• Essentially static human characteristics (e.g., length, volume, mass) available as tabulated anthropometric data

• COVERT Phenomena • Essentially dynamic human characteristics

• Outputs (e.g., motions, accelerations, forces) available using biomechanical techniques

• Inputs (e.g., can I see, in focus, the hammer’s head, the nail’s head, and my thumb?) available using sensory physiology techniques

• I/O coordination (e.g., hand-eye coordination – below level of conscious cognition)

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Behavioral Measurements Behaviors exist everywhere along continuum; here we are

concerned with information management behaviors • OVERT Phenomena

• Verbal & non-verbal (e.g., actions, including body language, eye contact, facial expressions, and gestures) using techniques of experimental psychology

• COVERT Phenomena • Affective (e.g., frustration with automation), cognitive (e.g.,

logic & perceived transparency of automation), and physiological aspects (e.g., ratio of sympathetic to parasympathetic autonomic activation) that may/may not drive overt behaviors - using exp. techniques such as: • ANALYTICAL – based upon prior information • SUBJECTIVE – based upon self-reporting (e.g., symptoms) • PERFORMANCE – using a secondary task • PSYCHOPHYSIOLOGICAL - measuring physiological functions

believed to co-vary with cognitive functions

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Social Measurements • OVERT Phenomena

• Communication & Coordination are overt aspects of activities, interactions, and sentiments (Homans, 1950)

• COVERT Phenomena • Conventions & Expectations (yielding norms

& roles = sets of norms) are covert aspects of activities, interactions, and sentiments

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Social Measurements (cont) • Measurement techniques are routinely used in

social anthropology, social psych. and sociology • Direct measurements

• Questionnaires & surveys • Interviews and observational (detached or

participatory) studies • Indirect measurements

• “Secondary analyses” of previously existing data • Computational methods of modeling social

phenomena (H. Simon, earliest in “Models of Man”,’57, Chapter 6 “Formal Theory of Interactions in Social Groups”)

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Cultural Measurements Not just great human cultures (e.g.,

Eastern, Middle Eastern, Western), but also specific sub-cultures (e.g., engineers, healthcare providers)

• OVERT Phenomena • Language (linguistics) & Artifacts (archeology) Artifacts = “physical secretions of organizations” Boulding, 1978

• COVERT Phenomena (value systems) • BCEM using cultural anthropology techniques (e.g.,

multi-sited ethnography)

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So …

• If someone says to you: “all that human-centric stuff is well and good, but I

cannot operationalize and measure it” DO NOT BELIEVE THEM!

• Maybe they cannot do it, but the knowledge and expertise to do so is readily available!

BUT YOU CAN’T DO IT ALL IN YOUR LAB DOWN THE HALL

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HUMAN FACTORS CONTRIBUTIONS What HF Engineers can contribute

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Human Factors Engineers • Important to realize that HF engineering has variety of

sub-disciplines, just like: • Hardware Engineers

• Mechanical, Electrical, Industrial, Civil, etc. • Software Engineers

• BIOS/Interface/Embedded, OS, Applications, etc. • HF Engineers

• Physical, Cognitive, Organizational, etc.

• No one HF engineer is usually expert is all the sub-disciplines!

• TEAMS of HF engineers are required, just like teams of hardware & software engineers

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So, how can HFEs contribute?

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Anatomy & Physiology • Anatomy is about the dimensions of humans

(length, area, volume, mass, etc.); in HF&E, a central interest is how they vary with gender, age, ethnicity, etc.

• Physiology is about how human internal systems work; in HF&E central interests are in: • perceptual (input) systems (e.g. visual, aural, tactile,

etc.) • effector (output) systems (e.g., muscular forces,

accelerations, etc.) • I/O coordination (e.g., hand-eye coordination)

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Some HF&E contributions: • Size, feel, color and arrangement of physical

controls & displays (“knobs & dials ergonomics”)

• Impact of their use with & without surgical gloves (e.g., grip strength issues, endurance)

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Psychology • Engineering psychology may be considered the

study of human behavior in the operation of tools; practitioners are concerned with the abilities & limitations of humans to sense, store, & process information and to act upon this … information management behaviors • Cognitive systems – human information

processing systems (e.g., thinking, analyzing, calculating, deciding, etc.)

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Psych. (cont.) • Affective systems – contribute to emotions

and moods that may include: anger, aversion, contempt, courage, despair, disgust, distrust, fear, guilt, hate, hope, joy, love, rage, panic, sadness, shame, surprise, terror ….

• Affective-Cognitive Interactions – modify cognitive processing, related to preparation for action, and involved in types of communication

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Some HF&E contributions: • Mental workload issues • Logic of operations issues • Design & realization of effective training

materials • Potential human emotional reactions to device

system behavior (anger, frustration, dissatisfaction) & related human performance deficits

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Social Environment • Directly or indirectly, all humans work in groups

or organizations • Communication & coordination systems,

within the group network, directly impact performance, safety, and individual satisfactions

• Systems of norms (acceptable & unacceptable context-dependent behaviors) & roles (sets of norms, such as gender roles, group leadership, etc.)

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Some HF&E contributions • How the specific work structures and the

related organizational structures modify performance issues: • during a crisis (e.g., patient in cardiac arrest) • related, for example, to boredom and reduced

vigilance, especially at the end of a work shift

• This is typically the concern of “macro-ergonomists” – practitioners involved in organizational design & management issues

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Cultural Environment • Not only are we considering the Great Human

Cultures, but also specific sub-cultures (e.g., engineers, clinicians)

• Language (e.g., engineer-speak vs. medical-speak) is a powerful modifier of communication & coordination

• Value systems (often based on religion and/or self-reference criteria) are the basis of motivations, which drive all behaviors

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Some HF&E contributions • Warnings (language) that are obvious to

engineers are often obscure to, or inefficient for, clinicians

• Language in design & construction of artifacts, e.g., operating manuals & training materials

• Clinician values (e.g. patient focus, minimizing time & effort, etc.) are typically VERY different from engineer values (e.g., using cutting-edge technology, focus on the equipment & methods, etc.)

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Physical Environment • The physical environment impacts, among

other things, user fatigue, mood, and perceptual/cognitive abilities; some parameters that impact these are: • Ambient Temperature • Ambient Humidity • Lighting (task & ambient) • Ambient Noise • Air Quality

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Some HF&E contributions • Light levels during day and night

operations affect tiredness and irritability • Consider “dynamic lighting” –

www.dynamiclighting.philips.com) • Involves changes in both intensity and

color temperature over work cycle • Indications that it improves concentration

& alertness with concomitant reduction in errors

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Human-centered Systems Engineering • Identifying new stakeholders, or new stakeholder NWDs, within

each iteration results in human-centered systems engineering (stakeholders are either human individuals or human organizations).

• This human focus continuously refines: • what should be built,

• tends to eliminate extraneous “features” and costs, • increases the probability of acceptance; • the five verifications identify technical errors; and • validation activities identify the mismatches between what

was agreed would be built and what actually was built. • It is this process that has the highest probability of reducing

economic, technical and operational risks.

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Group Exercise Continued (45min)

Continuing with your system & error: • Identify some HF factors that you think

might be involved • State what you think you would measure

and how … you may want to go back and update your Design Input(s)

• Guess how an HFE might contribute to solving identified problem

• Be prepared to present to class

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