Simulation of human error in a design loading task

Given that human error, particularly in design, causes a significant proportion of structural failures, it is of interest to develop a design task model that simulates the effect of human error in design. The development and analysis of a model for a typical design task (loading calculations for sizing a steel portal frame building) are described in the present paper. It is shown that human error in design loading calculations leads to a loss of structural safety. A comparison of the results of the design task model with available survey data for the same task suggests that such models can realistically represent the effect of human error on the modelled process.