Human reliability analysis methods for probabilistic safety assessment: Dissertation

Pekka Pyy

Research output: ThesisDissertationCollection of Articles


Human reliability analysis (HRA) of a probabilistic safety assessment (PSA) includes identifying human actions from safety point of view, modelling the most important of them in PSA models, and assessing their probabilities. As manifested by many incidents and studies, human actions may have both positive and negative effect on safety and economy. Human reliability analysis is one of the areas of probabilistic safety assessment (PSA) that has direct applications outside the nuclear industry. The thesis focuses upon developments in human reliability analysis methods and data. The aim is to support PSA by extending the applicability of HRA. The thesis consists of six publications and a summary. The summary includes general considerations and a discussion about human actions in the nuclear power plant (NPP) environment. A condensed discussion about the results of the attached publications is then given, including new development in methods and data. At the end of the summary part, the contribution of the publications to good practice in HRA is presented. In the publications, studies based on the collection of data on maintenance-related failures, simulator runs and expert judgement are presented in order to extend the human reliability analysis database. Furthermore, methodological frameworks are presented to perform a comprehensive HRA, including shutdown conditions, to study reliability of decision making, and to study the effects of wrong human actions. In the last publication, an interdisciplinary approach to analysing human decision making is presented. The publications also include practical applications of the presented methodological frameworks.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Lappeenranta-Lahti University of Technology LUT
  • Kalli, Heikki, Supervisor, External person
Award date7 Dec 2000
Place of PublicationEspoo
Print ISBNs951-38-5585-6
Electronic ISBNs951-38-5586-4
Publication statusPublished - 2000
MoE publication typeG5 Doctoral dissertation (article)


  • human reliability analysis
  • HRA
  • probabilistic safety assessment
  • human factors
  • decision making
  • expert judgement
  • simulator studies


Dive into the research topics of 'Human reliability analysis methods for probabilistic safety assessment: Dissertation'. Together they form a unique fingerprint.

Cite this