IE 486 Work Analysis & Design II

1. 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

2. 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.

3. 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

4. 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, F=+0.674 (25th percentile, F=-0.674)

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

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

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

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

9. 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.

10. 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

11. 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

12. 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

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

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

15. 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.