IE 486 Work Analysis

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IE 486 Work Analysis Design II

• Instructor Vincent Duffy, Ph.D.
• School of Industrial Eng. Ag. Bio Eng.
• Lecture 14 Workspace Design Anthropometry
  (cont.)
• Tuesday, March 6, 2007

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Today Thursday

• We began the discussion on Chapter 11 as a review
  of material you would have recognized from IE386.
  
• Though you have seen some of this content IE 386,
  the review becomes relevant especially at the
  beginning of the semester project.
• The semester project will include a
  computer-aided engineering exercise that relies
  on an understanding of the rationale for how to
  use the anthropometry databases.
• We started the discussion after reviewing the
  exam 1 solutions last week.
• We will finish it today after a brief
  introduction to the Purdue/HK Student Exchange
  currently available to IE students at Purdue for
  Fall 07
• During the presentation, we will return the exams
  that have now been mapped to ABET outcomes
• We will also return QOTD from recent past
  lectures.
• Since there will be no lecture on Thursday,
  please ask any questions about lab 3 at your
  convenience before Spring Break, or as needed.
• Also, please see the updated information on the
  course webpage about the remaining lab
  presentations on Lifelong Learning.

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Structural (static) and Functional (dynamic) data
in workspace design

• Anthropometry data can be classified into two
  types
• Structural data are measurements of the body
  dimensions in standard still (static) positions
• Functional data are obtained when body adopts
  various working postures

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Human variability

• Body dimensions are usually considered to be
  distributed (Normal)
• Percentiles
• X M F x s
• For example, if X is the percentile being
  accommodated,
• M is the mean (50 value), s is the std. dev.
  That can be determined (or used). F is the
  multiplying factor using Table 10.1 (eg. For 75th
  percentile, F0.674 (25th percentile, F-0.674)

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Please also consider additional design
information provided in Table 10.2
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Consider Fig. 10.3 on anthropometric measures
standing and sitting (p.253)
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See also Figs. 10.6 and 10.7 related to line of
sight and suggested controls placement
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See also Figs. 10.6 and 10.7 related to line of
sight and suggested controls placement
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Q.2. What is a 5th percentile female? A 95th
percentile male? (QOTD numbering today is a
continuation of the unfinished part of Lecture 12)

• What is the significance of these?
• A traditional check during design of a
  workstation that moves toward the extremes of the
  normal distribution curve to ensure that at least
  95 of male and 95 of female will be able to use
  the device (based on that particular measure.
• It is quite likely that once all relevant
  measures are considered (at the 5 female and or
  95 male anthropometry), that the fit will not
  include 95 of either group.
• Due to the previous idea that the whole does not
  equal the sum of the parts, and as mentioned in
  prior supplementary readings, clothing, etc. may
  cause changes in reach capabilities, etc.

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Q.3. Briefly outline the general principles for
workspace design.

• Clearance requirement for largest users
• Reach requirement for smallest users
• Consider maintenance requirements
• Include adjustability when possible/necessary
• Consider visibility and line of sight
• Component arrangement is related to the reach
  requirements
• for additional information see ch. 8 9 on
  Displays Controls

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Q.3. Briefly outline the general principles for
workspace design.

• Component arrangement is related to the reach
  requirements
• Frequency of use most frequently used placed in
  most convenience locations
• Importance components most crucial to achieving
  system goals should be in most convenient
  locations.
• Sequence of use components used in a sequence
  should be located next to each other
• Consistency Components used in other places
  should be located (spatially) consistent so as to
  reduce memory reqts.
• Others include Control-display compatibility,
  clutter avoidance and functional grouping

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Briefly describe the difference between design
for standing or seated work.

• Additional QOTD. What are the basic
  considerations of standing work?
• Standing is used when workers make frequent
  movements in large work areas, handle heavy or
  large objects, or exert large forces with their
  hands.
• Seated should be used for long duration jobs.
• For standing, consider
• Workstation height
• Different depending on precision, light or heavy
  work requirement (see Figure 10.9 on p.267).
  Precision workstation higher, heavier
  workstation lower.
• Overall seated or standing
• Work surface depth see fig. 10.9 on p.267
  10.10 on p.268. Shown in 1993 2004. Was it
  developed for ergonomics or time/motion analysis?
  What influence does that (underlying assumption
  of normal) have on results?
• Work surface inclination for reading tilt
  slightly

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Work surface height depth see fig. 10.9 on
p.267 10.10 on p.268
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Work surface height depth see fig. 10.9 on
p.267 10.10 on p.268
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Summary and conclusions

• Matching the physical layout of the workspace to
  the physical dimensions (anthropometry) and
  constraints of the user is necessary but not
  sufficient for workspace design.
• A worker may be able to reach, but dynamic
  aspects of task must be considered
• Worker may or may not be able to manipulate or
  lift without potential injury risk
• Work analysis an Introduction to Biomechanics
  were addressed in lecture 12.
• The Biomechanics discussion will continue after
  Spring Break and will include considerations and
  analysis tools for the dynamic aspects of task.