Ergonomic product and process design

Abstract

Ergonomic injuries are not the result of acute events. An ergonomic injury develops gradually from continued actions combining force, motion repetition, posture, and duration. Because these injuries accrue over time, it is often difficult to determine their causes. Lacking a clear causal link, it is difficult to justify investments that are intended to prevent ergonomic injuries. A large computer manufacturer, Dell Inc, is targeting significant reductions in their factory injury rates. This thesis describes the evaluation of two desktop computer manufacturing facilities. As part of this work, OSHA logs from 2002 were analyzed, injury costs were collected, factory workers were surveyed, and biomaterials associated with ergonomic injuries were studied. The analysis of the OSHA logs determined that 70% of factory injuries were ergonomic in nature and that a majority of the ergonomic injuries occurred as a result of work in the computer assembly (build) area. The costs associated with ergonomic injuries were computed on a cost per box (CPB) basis, a common metric used throughout Dell factories to determine financial impact. In order to evaluate, improve, and monitor the ergonomic factors on the factory floor, an evaluation tool for product and process design was developed. This tool incorporates risk factors of force, motion repetition, and posture while determining ergonomic scores for products and process steps. Tool validation was achieved by comparing ergonomic scores with worker product preferences, as revealed by an employee survey. Currently, the ergonomic evaluation tool is being used by the Environmental, Health, and Safety (EHS) Department at Dell. A greater understanding of the causes behind ergonomic injuries, combined

(cont.) with use of the evaluation tool, is contributing to Dell's efforts to continuously reduce the occurrence of ergonomic injuries and associated costs.