A Human Reliability Analysis Approach Based on the Concepts of Meta-Operation and Task Complexity

To avoid the difficulties in human error data collection or elicitation and make Human Reliability Analysis (HRA) more generic, a new HRA approach is proposed based on meta-operation identification and task complexity measurement. In this approach, a task is decomposed into metaoperations which is defined as the smallest identifiable operation or activity exhibited in the performance of a task. An eye-tracking experiment was conducted with a conclusion that the metaoperation description model of procedure tasks is reasonable. Then action complexity of these metaoperations is measured. Experiment results indicate that the complexity scores have significant correlation with and are able to explain high percentage of variations of task completion time and error rate. Thus it is possible to establish a generic model for human error probability (HEP) based on task complexity. We intend to provide HEP parametric models rather than HEP tables. For the improvement of task complexity quantification, a survey with 69 licensed NPP operators was conducted to identify complexity factors in main control rooms. Significant factors will be later included into the complexity quantification model. In the proposed method, most PSFs are treated as complexity factors and thus not used as modifiers as in many existing HRA methods.