Assessing human errors in sensitive jobs using two methods, TAFEI and SHERPA: A case study in a high-pressure power post

The work process is very important in complex jobs, so that if you forget or do not do it for any reason, it will have unpleasant consequences. The aim of this study was to identify and evaluate the human errors in sensitive jobs from two perspectives of human error identification in a high-voltage post station.

In this descriptive study, TAFEI and SHERPA techniques were employed to identify the operator's error. The necessary information was obtained by directly observing the human activities, interviewing and reviewing the tasks and sub-tasks with HTA method. The exploited techniques were thence compared in terms of error detection and applied field.

The results of matrix table in the job task using TAFEI method showed 29 cases of illegal transfer, so 29 human errors were identified; while totally 25 errors were identified by SHERPA method.

The results of this study show that the TAFEI method performs better in identifying the number of human errors in the task sequence step. On the other hand, the SHERPA method can cover the weaknesses of the TAFEI method and provide the level of risk. Accordingly, it is recommended that the analyst consider the different available HEI techniques and apply the one that he/she considers the most suitable for their need.