Comparison of Two Human Error Evaluation Techniques (HET and SHERPA) in Gas Supply Operations using AHP

The development of residential and industrial areas has led to increasing gas consumption and overcrowding in gas supply networks. Accordingly, hazards and risks caused by human errors, processing and mechanical failures in pipelines, and gas leaks are on a rise. Several techniques have been so far proposed for identifying and controlling human errors. The main purpose of this study was to compare two human error evaluation techniques, namely, Human Error Template (HET) and Systematic Human Error Reduction and Prediction Approach (SHERPA) in gas supply operations using the analytic hierarchy process (AHP) to select a suitable method.

This cross-sectional descriptive study was to identify the human error modes in one of the gas supply projects operating by Kurdistan Gas Company, Kurdistan, Iran. Different tasks in gas supply operations were accordingly determined by the health, safety, and environment (HSE) unit, then the ones susceptible to human errors were selected and analyzed through task analysis technique. The next step was to weight and rank the human errors by evaluating indexes based on many variables including accuracy, sensitivity, and quantity of the errors as well as usability, time, and education analysis using the Expert Choice software (ver. 11).

According to the findings of this research, the criteria were ranked based on accuracy (0.339), sensitivity (0.322), quantity of errors (0.118), usability (0.116), time (0.056), education (0.050), and analysis. The inconsistency ratio was also equal to 0.1, which meant that the subjective judgments were accepted.

The results also showed that the analysis of human errors, using the HET, required less training and time, while the number of the detected errors and applicability in the SHERPA was greater. Considering the weight of the criteria, their importance in determining the superior technique and the weight of each one in relation to the criteria, the contribution of that method in the relevant criterion was expressed. Calculating the final weight of the techniques revealed that SHERPA with a weight of 0.53 was more practical compared with HET with a weight of 0.46.