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IE 486 Work Analysis & Design IIIE 486 Work Analysis & Design II Instructor: Vincent Duffy, Ph.D.Instructor: Vincent Duffy, Ph.D.

School of Industrial Eng. & Ag.& Bio Eng.School of Industrial Eng. & Ag.& Bio Eng.Lecture 14 – Workspace Design & Lecture 14 – Workspace Design &

Anthropometry Anthropometry (cont.)(cont.)

Tuesday, March 6, 2007Tuesday, March 6, 2007

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Today & ThursdayToday & Thursday

We began the discussion on Chapter 11 as a review of material you We began the discussion on Chapter 11 as a review of material you would have recognized from IE386. would have recognized from IE386. – Though you have seen some of this content IE 386, the review Though you have seen some of this content IE 386, the review

becomes relevant especially at the beginning of the semester project.becomes relevant especially at the beginning of the semester project.– The semester project will include a computer-aided engineering The semester project will include a computer-aided engineering

exercise that relies on an understanding of the rationale for how to use exercise that relies on an understanding of the rationale for how to use the anthropometry databases.the anthropometry databases.

– We started the discussion after reviewing the exam 1 solutions last We started the discussion after reviewing the exam 1 solutions last week.week.

– We will finish it today after a brief introduction to the Purdue/HK Student We will finish it today after a brief introduction to the Purdue/HK Student Exchange currently available to IE students at Purdue for Fall ’07Exchange currently available to IE students at Purdue for Fall ’07

During the presentation, we will return the exams that have now been During the presentation, we will return the exams that have now been mapped to ABET outcomesmapped to ABET outcomesWe will also return QOTD from recent past lectures.We will also return QOTD from recent past lectures.

Since there will be no lecture on Thursday, please ask any Since there will be no lecture on Thursday, please ask any questions about lab 3 at your convenience before Spring Break, or questions about lab 3 at your convenience before Spring Break, or as needed. as needed. Also, please see the updated information on the course webpage Also, please see the updated information on the course webpage about the remaining lab presentations on Lifelong Learning.about the remaining lab presentations on Lifelong Learning.

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

Anthropometry data can be classified into Anthropometry data can be classified into two types: two types: – Structural data are measurements of the body Structural data are measurements of the body

dimensions in standard still (static) positionsdimensions in standard still (static) positions– Functional data are obtained when body Functional data are obtained when body

adopts various working postures adopts various working postures

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Human variabilityHuman variability

Body dimensions are usually considered to be Body dimensions are usually considered to be distributed (Normal) distributed (Normal)

PercentilesPercentilesX = M + F x sX = M + F x sFor example, if X is the percentile being For example, if X is the percentile being

accommodated, accommodated, M is the mean (50% value), s is the std. dev. That can M is the mean (50% value), s is the std. dev. That can

be determined (or used). F is the multiplying factor be determined (or used). F is the multiplying factor using Table 10.1 (eg. For 75using Table 10.1 (eg. For 75thth percentile, F=+0.674 percentile, F=+0.674 (25(25thth percentile, F=-0.674) percentile, F=-0.674)

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Please also consider additional design Please also consider additional design information provided in Table 10.2information provided in Table 10.2

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Consider Fig. 10.3 on anthropometric Consider Fig. 10.3 on anthropometric measures: standing and sitting (p.253) measures: standing and sitting (p.253)

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See also Figs. 10.6 and 10.7 related to line See also Figs. 10.6 and 10.7 related to line of sight and suggested controls placementof sight and suggested controls placement

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See also Figs. 10.6 and 10.7 related to line See also Figs. 10.6 and 10.7 related to line of sight and suggested controls placementof sight and suggested controls placement

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Q.2. What is a 5Q.2. What is a 5thth percentile female? A 95 percentile female? A 95thth percentile male? percentile male?

(QOTD numbering today is a continuation of the unfinished part of Lecture 12)(QOTD numbering today is a continuation of the unfinished part of Lecture 12)

What is the significance of these?What is the significance of these?– A traditional check during design of a workstation that A traditional check during design of a workstation that

moves toward the extremes of the normal distribution moves toward the extremes of the normal distribution curve to ensure that at least 95% of male and 95% of curve to ensure that at least 95% of male and 95% of female will be able to use the device (based on that female will be able to use the device (based on that particular measure. particular measure.

– It is quite likely that once all relevant measures are It is quite likely that once all relevant measures are considered (at the 5% female and or 95% male considered (at the 5% female and or 95% male anthropometry), that the fit will not include 95% of either anthropometry), that the fit will not include 95% of either group. group.

Due to the previous idea that the whole does not equal Due to the previous idea that the whole does not equal the sum of the parts, and as mentioned in prior the sum of the parts, and as mentioned in prior supplementary readings, clothing, etc. may cause supplementary readings, clothing, etc. may cause changes in reach capabilities, etc. changes in reach capabilities, etc.

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

ClearanceClearance requirement for requirement for largestlargest users users

ReachReach requirement for requirement for smallestsmallest users users

Consider Consider maintenancemaintenance requirements requirements

Include Include adjustabilityadjustability when possible/necessary when possible/necessary

Consider Consider visibilityvisibility and line of sight and line of sight

Component arrangementComponent arrangement is related to the is related to the reach requirementsreach requirements– for additional information see ch. 8 & 9 on Displays for additional information see ch. 8 & 9 on Displays

& Controls& Controls

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

Component arrangement is related to the Component arrangement is related to the reach requirementsreach requirements– Frequency of useFrequency of use – most frequently used placed in most – most frequently used placed in most

convenience locationsconvenience locations– ImportanceImportance – components most crucial to achieving – components most crucial to achieving

system goals should be in most convenient locations.system goals should be in most convenient locations.– Sequence of useSequence of use – components used in a sequence – components used in a sequence

should be located next to each othershould be located next to each other– ConsistencyConsistency – Components used in other places should – Components used in other places should

be located (spatially) consistent so as to reduce memory be located (spatially) consistent so as to reduce memory reqts. reqts.

– Others include: Others include: Control-display compatibilityControl-display compatibility, , clutter clutter avoidanceavoidance and and functional groupingfunctional grouping

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

Additional QOTD. What are the basic considerations of Additional QOTD. What are the basic considerations of standing work?standing work?– Standing is used when workers make frequent movements Standing is used when workers make frequent movements

in large work areas, handle heavy or large objects, or exert in large work areas, handle heavy or large objects, or exert large forces with their hands.large forces with their hands.

– Seated should be used for long duration jobs.Seated should be used for long duration jobs.– For standing, consider: For standing, consider:

Workstation heightWorkstation height– Different depending on precision, light or heavy work requirement (see Different depending on precision, light or heavy work requirement (see

Figure 10.9 on p.267). Precision – workstation higher, heavier –Figure 10.9 on p.267). Precision – workstation higher, heavier –workstation lower.workstation lower.

– Overall seated or standing…Overall seated or standing…Work surface depth – see fig. 10.9 on p.267 & 10.10 on p.268. 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 Shown in 1993 & 2004. Was it developed for ergonomics or time/motion analysis? What influence does that (underlying time/motion analysis? What influence does that (underlying assumption of ‘normal’) have on results?assumption of ‘normal’) have on results?Work surface inclination – for reading – tilt slightlyWork surface inclination – for reading – tilt slightly

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Work surface height & depth – see Work surface height & depth – see fig. 10.9 on p.267 & 10.10 on p.268fig. 10.9 on p.267 & 10.10 on p.268

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Work surface height & depth – see Work surface height & depth – see fig. 10.9 on p.267 & 10.10 on p.268fig. 10.9 on p.267 & 10.10 on p.268

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Summary and conclusionsSummary and conclusions

Matching the physical layout of the workspace to Matching the physical layout of the workspace to the physical dimensions (anthropometry) and the physical dimensions (anthropometry) and constraints of the user is necessary but not constraints of the user is necessary but not sufficient for workspace design.sufficient for workspace design.A worker may be able to reach, but dynamic A worker may be able to reach, but dynamic aspects of task must be consideredaspects of task must be considered– Worker may or may not be able to manipulate or lift Worker may or may not be able to manipulate or lift

without potential injury riskwithout potential injury risk– Work analysis & an Introduction to Biomechanics Work analysis & an Introduction to Biomechanics

were addressed in lecture 12. were addressed in lecture 12. – The Biomechanics discussion will continue after The Biomechanics discussion will continue after

Spring Break and will include considerations and Spring Break and will include considerations and analysis tools for the dynamic aspects of task. analysis tools for the dynamic aspects of task.