Ergonomics In Manual Workspace Design: Current Practices And An Alternative Computer-assisted Approach (designer Survey, Modeling, Manufacturing, Cad, Operator Performance).

Abstract

A traditional objective of ergonomics has been to improve workspace designs through consideration of the human operator. While many reasons may explain a designer's failure to consider ergonomics in human-workspace systems, this research focused on the limitations due to (1) methods of information presentation which are incompatible with design strategies, and (2) difficulties in assessing multiple design factor interdependencies. A designer survey, administered to 40 engineers in 5 companies, quantified ergonomic design information needs and activities for three work-space applications (i.e., manual assembly, machine loading, and manual materials handling). Survey responses also identified the scope, user interface and specific input/output formats for a computer-based ergonomic design system. Distinct differences in design initiation, ergonomic information sources and design goals existed between preliminary design and detailed final design activities. A lack of complete information, reliance on previous designs as information sources and concentration on functional requirements were unique to the preliminary design stage. Reduced flexibility in design alternatives, concern for workplace health and safety, and a desire for design optimization existed in the final design stages. A complimentary research effort developed comprehensive models for operator, workspace and task information using available computer-based ergonomic analysis tools which predicted worker static strengths, reach capabilities and task motion times performance. The framework and prototype system implementation allowed interactive graphic workspace layout, task element description and operator and ergonomic design criteria specification. It provided indicators of operator performance limitations resulting from specific design conditions, and contained mechanisms for modifying and evaluating alternate designs. Persons using the system for preliminary design obtained ergonomic information through presentation of design guidelines, which identified regions of acceptable design solutions. Those involved in final design performed multiple ergonomic analyses with results conveyed through integrated tables, performance graphs, and three-dimensional enfleshed operator and workspace layouts. Formalized system demonstrations on an HP-1000 mini-computer were effective in predicting operator physical stresses associated with different tasks and investigating design alternatives. Areas for future research were identified and include development of enhanced operator performance models and organizational issues, such as where the system should be located and what type of user training is needed.