The State of Human Reliability Analysis

This chapter provides a basic introduction to the issue of human reliability analysis (HRA) and the basic motivation for HRA (the pervasiveness of human erroneous actions and the widespread tendency to see human action failures as the causes for accidents and incidents). It explains the need to understand the nature of the cause-effect dependencies that can explain the occurrence of undesirable events, and the basis for preventing them. It highlights the ability to make accurate predictions on the ability to analyze correctly past events, and focuses on the systems that have often been the focus of considerable concern because of large-scale accidents. It defines principles of reliability and error through equally valid analysis for seemingly simpler systems, such as automatic ticketing machines, private cars, and food and drink machines. The importance of HRA context is that human performance is determined by human cognition (the technology plus the organization), and therefore, it is important to be able to account for cognitive reliability.