The objective of this publication is to describe the state of the art framework of human reliability analysis (HRA) with a detailed description of HRA procedures and factors to be considered in the process of an HRA. It is intended to be applied for both new and existing nuclear installations. This publication is intended to be used by a broad spectrum of analysts, for example probabilistic safety assessment (PSA) practitioners and human factor engineers, as well as regulatory bodies, utilities, research institutes, technical support organizations and designers of nuclear installations.