Task modelling in computer-aided workplace design

Injury in the workplace continues to be a significant problem in industry with implications for both the health and well being of the worker and the impact on production schedules and costs. Historically regulations have been enforced to reduce the incidence and severity of injury by limiting the load that various categories of worker may handle. This approach prevents gross overloading of the worker but does not consider the manner or frequency at which the worker performs the task. Current United Kingdom legislation avoids imposing absolute limits but presents guidelines indicating maximum load zones. These may be used for screening existing tasks and help to identify potential hazards. More refined models have been suggested but these also fail to consider the posture used to reach the load. To fully appreciate at the design stage the posture a worker may adopt demands the use of computer aided design tools. This allows recognition of the spatial fit, sequence and reach requirements for performing the task and avoids imposing undesirable postures. Further enhancement is possible by simulating the worker’s response to imposed task related loads. This approach allows an index of relative loading to be calculated for the posture and used to interactively improve the design of the workplace.