A participant-observer study of ergonomics in engineering design: how constraints drive design process

Too often, ergonomics is relegated to being a "post-design" evaluation, lea ving ergonomists little opportunity to make significant and important desig n changes. One way to start attacking this problem is to study the process of design and, in particular, ergonomics in design. This article describes the findings from a four-month long participant-observer study of the relat ionship between ergonomics and engineering design. The study was conducted in the context of a large, interdisciplinary project consisting of design o f a control room for a nuclear power plant. It was observed that designers and ergonomists must negotiate through a changing web of constraints from m any sources. The impact that these constraints had on the course of the des ign was documented. A model is developed based on the abstraction hierarchy (Rasmussen, 1985, IEEE Trans. Systems Man Cybernet. SMC-15, 234-243; 1990, Int. J. Ind. Ergon. 5, 5-16) which shows the interaction of conflicting go als as ergonomists and other designers attempt to solve a complex design pr oblem. This model leads to several insights: (1) locally optimal ergonomic designs may not be globally optimal, (2) ergonomists can improve their solu tions by understanding the goals of other designers, and (3) future tools t o aid ergonomists must be compatible with the constraint-rich environments in which they work. (C) 1999 Elsevier Science Ltd. All rights reserved.