Unit 1: Human Factors and Ergonomics

• Human Factors


  The combination of ergonomics and anthropometrics
• Aims of Human Factors


  • Reduce stress and fatigue on people
  • Increase safety
  • Increase ease of use
  • Enhance operational comfort
  • Improve system performance, reliability and maintenance
• Ergonomics


  The application of scientific information concerning the relationship of human beings to the design of objects, systems and environments
• Physical ergonomics


  Deals with work related subjects of: posture; worksite development operating layout; material handling; repetitive stress and movement; repetitive stress injuries and musculoskeletal disorders; and occupational safety and health
• Cognitive ergonomics


  Concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system

  
• Organisational ergonomics


  Subjects include communication, work design, shift (work hours) management, crew resource management, teamwork, virtual organizations, telework, and quality management
• Anthropometric data


  Sub-classified as Static Data and Dynamic Data
• Structural Anthropometric data


  Static Data refers to measurements taken while the subject is in a fixed or standard position, e.g. height, arm length
• Functional Anthropometric data


  Dynamic Data refers to measurements taken during physical activities, e.g. crawling height, overhead reach and a range of upper body movements
• Tools used to collect Anthropometric Data


  • Sliding Callipers
  • Cloth Tape
  • Sitting height meters
  • Stadiometer
• Percentiles


  Tell you whether the measurement given in the tables relates to the 'average' person, or someone who is above or below average in a certain dimension
• Clearance


  The minimum distance required to enable the user group into or through an area
• Reach


  Also known as the workspace envelope, a 3-dimensional space within which you carry out physical work activities when you are at a fixed location
• Workspace envelopes should be designed for the 5th percentile of the user population, which means that 95% of users will be able to reach everything placed within the envelope
• Adjustability


  Certain products tend to be available in different sizes or with adjustability built in as there really is no 'one size fits all'
• Range of sizes vs adjustability


  Clothing comes in a range of sizes, while children's car seats are adjustable to allow for a range of sizes and a growing child
• Ergonome


  A 2D scaled physical anthropometric model based on a specific percentile human forms, used with drawings to consider the relationship between the size of an object and people
• Manikin


  A jointed 3D model of the human body, useful for assessing the relationship of body parts to spatial arrangements represented by a 3D model
• Human beings vary psychologically in complex ways, and any attempt by designers to classify people into groups merely results in a statement of broad principles that may or may not be relevant to the individual
• Cognitive psychology/cognitive ergonomics


  Concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system

  
• Methods for collecting Psychological factor data

  • Observation
  • Surveys & Interviews
  • Standardized Testing
  • Case Studies
• Nominal Data Scale


  Used in classification or division of objects into discrete groups, identified with a name, without providing any measurement within or between the categories
• Ordinal Data Scale


  Deals with the order or position of items, arranged in a hierarchical order, without quantitative assessment
• Interval data scale


  Organised into even divisions or intervals of equal size, without a true zero point
• Ratio data scale


  Has a true zero point, allowing comparison of differences between numbers
• Examples of Psychological factors


  • Smell
  • Light
  • Sound
• A ratio scale allows you to compare differences between numbers
• Examples of Psychological factors


  • Smell
  • Light
  • Sound
  • Taste
  • Texture
  • Temperature
  • Value
• Smell


  Important in food, perfumes, candles, deodorants, chemicals. Unpleasant odors are added to chemicals to warn people
• Light


  The level of illumination should increase as the tasks becomes more precise; for example the illumination required for a surgeon is brighter than the illumination needed for a corridor
• Lighting


  Effects on ambience and mood, e.g. lighting in restaurants – gentle, calming, stimulating
• Uses of sound


  • Provide information such as warning signal (fire alarm or alarm)
  • Sound for reassurance that the product is working ex. Watches
  • Feedback , whistling kettles, reversing trucks
• Sound


  Can be positive in the environment such as playing music in an exhibition. Noise can also be negative in a workspace, that's why open plan offices use screens to reduce noise
• Taste


  Important in food, it must have a good taste to sell well. Responses to taste are also a factor of culture and experience
• Texture


  Shapes and textures improve products and make them easier to use, for example bottle tops, handles fabrics and non-slip floors, smooth worktops in kitchen
• Temperature


  Clothing is an important part of a comfortable work environment but the environment must be controlled regardless of the outside climate. How the user responds to different environmental factors, for example, how warm or cold work environments can affect the performance of an individual. A range of comfort zones will exist based on body mass, manner of dress or even physiological changes that can be developed from exposure to a particular temperature or environment over time
• Value


  May be perceived as a function of cost, features, prestige, rarity etc. or a combination of these factors
• Human information processing systems


  Considering inputs, processes (sensory, central and motor) and outputs

  
• Examples of Environmental factors


  • Noise
  • Lighting
  • Temperature
  • Humidity
  • Vibration
• Environmental factors


  May affect: hearing, vision, general comfort and health