An overview of the evolution of human reliability analysis in the context of probabilistic risk assessment.

Abstract

Since the Reactor Safety Study in the early 1970's, human reliability analysis (HRA) has been evolving towards a better ability to account for the factors and conditions that can lead humans to take unsafe actions and thereby provide better estimates of the likelihood of human error for probabilistic risk assessments (PRAs). The purpose of this paper is to provide an overview of recent reviews of operational events and advances in the behavioral sciences that have impacted the evolution of HRA methods and contributed to improvements. The paper discusses the importance of human errors in complex human-technical systems, examines why humans contribute to accidents and unsafe conditions, and discusses how lessons learned over the years have changed the perspective and approach for modeling human behavior in PRAs of complicated domains such as nuclear power plants. It is argued that it has become increasingly more important to understand and model the more cognitive aspects of human performance and to address the broader range of factors that have been shown to influence human performance in complex domains. The paper concludes by addressing the current ability of HRA to adequately predict human failure events and their likelihood.4

Causal Pathways Leading to Human Failure Events in Information-Gathering System Response Activities

“…HRA is a useful tool for characterizing this human error in a wide variety of domains so that it can be acknowledged and mitigated. There has been a need for cognitively  Corresponding author email address: clevine1@umd.edu realistic, yet quantifiable, models that account for the full range of contexts inherent to human operation [3]- [7]. While older models frequently lack this psychological realism, newer models may lack quantification schemes that are feasible in practice.…”