The Role of Human Factors in Systems Engineering

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The Role of Human Factors in Systems Engineering

• S. Camille Peres, Danielle Smith, Carroll
  Thronesbery

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Overview

• Purpose
• To help systems engineers (SEs) understand what
  HFEs do, how they do it, and how SEs can make
  good use of HFE contributions
• To open a dialogue between SEs and HFEs best
  method for participation in the systems
  acquisition process
• What is Human Factors?
• Examples of HF gone wrong
• What does SEs need to understand about HFE?
• What does HFEs need to understand about SE?
• Where do we go from here?

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Human Factors is

• A branch of applied science aimed at matching
  machines and tasks with the abilities of their
  human operators.
• The study, discovery, and application of
  information about human abilities, human
  limitations, and other human characteristics to
  the design of tools, devices, machines, systems,
  job tasks and environments for effective human
  performance.
• -Alphonse Chapanis

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Examples of Human Performance Issues in Complex
Systems

• Gemini 9 Gene Cernan (1966)
• "Every time I'd push or turn a valve, it would
  turn my entire body in zero gravity. I had
  nothing to hold on to. And we take for granted
  gravity, because we can do that kind of work with
  ease if something is holding our feet to the
  ground. Nothing was holding me anywhere."
• Face visor fogged up due to profuse sweating
  hed rub his nose on the faceplate to create a
  peephole.
• Once in the vehicle, face was extremely flushed
  (nearly passed out) hands were so swollen that
  when he pulled off the suit's gloves, some of his
  skin came with them. It was so much of a relief
  that he didn't care.
• http//www.vectorsite.net/tamrc_16.html

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More recent example

• International Space Station (ISS)
• 2-week drop in vehicle pressure could have
  resulted in the crews needing to evacuate (2004)
  
• Determined a hose near window responsible for
  pressure loss.
• http//www.space.com/missionlaunches/exp8_update_0
  40123.html
• Perspectives on solutions
• SEs - all connections on hoses need a higher
  tolerance for tugging
• HFEs - put mobility aid near all windows(not
  have hose connections look like handles)

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Focus of SEs and HFEs

• Both SEs and HFEs are vested in system success
• Focus of System Engineers
• Integration of ALL systems to insure
• system success
• stakeholder satisfaction
• Focus of Human Factors Engineers
• Integration of the needs of the human into ALL
  systems to insure
• optimal performance
• safety
• This ultimately contributes to system success and
  stakeholder satisfaction

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Human Factors Engineers do Human Centered Design
Graphic from Deborah Mayhew - http//drdeb.vineyar
d.net/index.php?loc11nloc1
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Incorporation into SE Process

• Apply established methods and design principles
  throughout design cycle for any system that comes
  into contact with human users or maintainers

Design Formulation / Conceptual Design
Design Implementation
Ops
Mission Definition
System Definition
Prelim Design
Final Design
Fab Int
Deployment
Ops

• MDR

• SRR

• SDR

• PDR

• CDR

• FRR

• ORR

• Operational Analysis
• Benchmarking

• Usability evaluation (low-fi)
• Function allocation workload

• Concept of Operations (ConOps)
• Preliminary Function Allocation
• Task Analysis

• User Interface Specification
• Usability evaluation (med-fi)

• Performance-based requirements (design option
  trade-off analyses)
• Workload analyses

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Efficiency of Human-Centered Design

• Including HFEs throughout process can decrease
  Total Cost of Ownership
• Incorporating HF early in design cycle may impact
  initial cost and schedule but will reduce
  long-term costs (e.g., Training, Maintenance,
  Staffing, Safety)
• E.g. Military Human-Systems Integration programs
  MANPRINT
• Currently
• HF is often only utilized near the end of the
  development cycle
• This results in a low Return on investment (ROI)
• If a design issue is not addressed during
  conceptual design, it is 10 times more costly to
  fix it during development, and 100 times more
  costly to fix it after the product is released
  (Pressman, 1992)

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Whats different now?

• Historically, development and implementation of
  technology has been the primary focus of many
  industries
• Work-arounds and training have worked as
  band-aids for poor user interface
• Currently, with the increasing need for the human
  to be autonomous, this will no longer suffice
• NASA - Mission control personnel cannot augment
  crew performance with Mars missions
• Software design - Increasing competition has made
  usability a key selling point

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How can HFE help?

• HFEs know how to collect (and can help
  prioritize) stakeholder needs, wants, and desires
• HFEs can help with system validation ensure the
  new system provides necessary and useful human
  task support
• HFEs know how to verify human performance
  requirements

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This talk will illustrate

• At a minimum HFE can contribute to SE team by
• Improving Concept of Operations (ConOps) and
  verifying its usefulness with end users
• Performing early design trade analyses
• human-system capabilities, system cost, task
  allocation
• Assisting with preliminary hazard analysis
• Assist with matching early requirements and
  design to task descriptions and human performance
  capabilities

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Early Concept Definition

• Identify how system will be used
• Systems engineer know implied system functions
  and requirements
• If HFEs privy to this information, can establish
  necessary human-task support for integrated
  human-system performance
• Specialized methods and techniques for obtaining
  accurate, useful information from end users
• Identify users needs for task support
  requirements
• Provide feedback to users about implications for
  task support
• Get evaluations from users about value of planned
  task support
• Informs a well defined Concept of Operations
  (ConOps) for improved human-system performance

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Early Design

• If SEs continue to include HFEs
• Further refinement of ConOps
• User task descriptions
• Overall profile of tasks (timing, workload, etc)
• Preliminary workspace layout
• Based on task analyses and system engineering
  constraints
• Preliminary Hazard Analysis
• User task features to monitor errors, workload
• Identify potential hazards to safety
• Identify potential controls for hazards
• Identify metrics to know when controls are
  effective
• Benefit to SE Identify design issues early,
  minimize training, document due safety diligence,
  etc.

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How we can work together

• Requirements
• HF engineers can
• Identify human engineering requirements by using
  mockups iteratively
• If Systems engineers will
• Incorporate conceptual mock-ups into the design
  cycle

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How we can work together

• Detailed Design
• HF engineers can
• Develop detailed hardware design standards and
  software/procedures style guides
• If Systems engineers will
• Ensure that the standards and style guides are
  appropriately applied within the engineering
  phases and also require that engineers follow HF
  standard guidelines and style guide.
• This reduces the need for full human-factors
  reviews of every project. Thus facilitating
  project development and the SE review process

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How we can work together

• Verification
• HF engineers can
• Identify appropriate metrics for evaluation
• If Systems engineers will
• Work with HFE to incorporate both qualitative and
  quantitative metrics into verification plans as
  appropriate

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What HFEs need to do

• What they do best
• Know thy USER!

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Educate System Engineers

• Often systems designers are not familiar with HFE
  expertise beyond anthropometry and usability
• Educate them on HFEs expertise
• General knowledge of human performance and error
  tendencies
• Empirical methods to address specific system
  questions with end users
• Help overcome misconceptions, like.
• Effective Human-Systems IntegrationUsers lead
  efforts
• No, users often tell us what doesnt work, not
  what will work
• HF only needed once product design has been
  finalized

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Meet SEs needs

• Systems experts co-ordinate many systems
• HF experts should know (and show it) the context
  of system use
• SEs need understandable requirements so they can
  integrate them into other systems
• and tools/straightforward methods to verify those
  requirements
• SEs need appropriate information to make informed
  design trades
• Systems designers need help with design
• Increase HFEs availability to systems designers
  and make meaningful contributions to design
  throughout process

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Agree on expectations!

• HF engineers often do not clearly outline goals
  to customers
• Often, customers (engineers) are expecting a
  number, not a recommendation
• HFE SE should work together to draft
  meaningful, verifiable, system-focused
  requirements

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To recap

• Now you know
• What Human Factors Engineering is
• Where Human Factors Engineering can help
• When Human Factors Engineering can help
• What Human Factors Engineering needs to do for SE
• But

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We dont know what we dont know

• Only Systems Engineers can tell us
• Where are our training programs falling short?
• What do we need to know more about or better?
• Should we
• Teach other types of engineers how to include
  Human system interface issues into their
  deliverables?
• Have HF at the table during system/project
  planning?
• Have those who are at the table be more
  knowledgeable regarding the Human as a system?

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Thank you

• Contact information
• S. Camille Peres PeresSC_at_uhcl.edu
• Danielle Smith dpaigesmith_at_gmail.com
• Carroll Thronsbery carroll.g.thronesbery_at_nasa.gov
  
• Houston HFES HoustonHFES.org
• INCOSE INCOSE.org