The systematic integration of human factors into safety analyses: An integrated engineering approach

The performance of the Human Reliability Analysis (HRA) and integration of its outcomes into QRA schemes remains a quite difficult and complex task to perform. Even worse is the assessment of Organisational Reliability Assessment (ORA). The reasons of this difficulty mainly lay on the absence of a generically accepted paradigm that enables engineers to include systematically H&OF (Human & Organisational Factors) into the analysis. Broadly speaking, engineering approaches very often account for Error of Omission (EOO) forgetting the Errors of Commission (EOC), and, on top of that, they do not make any macro distinction between preand post-initiating human failures. This paper offers a paradigm on how to integrate H&OF into safety analysis by means of the Recursive Operability Analysis (ROA), which has been adapted to accommodate H&OF, and renamed Integrated Recursive Operability Analysis (IROA). By means of a practical example, the method will illustrate how to account for H&OF in a systematic and consistent manner using an engineering approach. The paper will even provide a paradigm for the construction of Integrated Fault Trees (IFT) consistent with the IROA framework. This is the author post-print version of an article published on Reliability Engineering and System Safety, Vol. 93 (12), pp. 19111921, 2008 (ISSN 0951-8320). The final publication is available at http://dx.doi.org/10.1016/j.ress.2008.03.029 This version does not contain journal formatting and may contain minor changes with respect to the published edition. The present version is accessible on PORTO, the Open Access Repository of the Politecnico of Torino, in compliance with the publisher’s copyright policy. Copyright owner: Elsevier.