Human Error Assessment and Management among Isfahan Oil Refinery Control Room Operators by SHERPA Technique

In many work environments with sensitive and complex technologies, human errors are very important since they may lead to catastrophes. Therefore, it is necessary to recognize and find out causes of human errors to prevent and limit their dreadful consequences. This study aimed to identify, assess and control human errors in the distillation unit of Isfahan Oil Refinery.

This study was performed in 2010. Data was collected using task observation and interviewing safety authorities, unit and shift supervisors and operators. Finally, 8 critical tasks were determined. Then, Hierarchical Task Analysis (HTA) was conducted and human errors in each task were identified by Systematic Human Error Reduction Prediction Approach (SHERPA) technique.

After analyzing SHERPA work sheets, 198 human errors were identified including 134 (67.64%) action errors, 23 (11.61%) checking errors, 11 (5.6%) communication errors, 24 (12.12%) retrieval errors and 6 (3.03%) selection errors. Overall, the possibility of 64% of human errors among control room operators was assessed as "low" while 36% had a "moderate" possibility. In addition, although 59% of the identified errors of control room operators required no recovery, 29% resulted in sensitive outcomes.

The results showed that SHERPA technique can be used as an effective method to detect human errors in the control room of sensitive units of oil refineries.