Modelling of the human factor using petri nets

Usually, in the reliability analysis performed for a complex system, we determine the success probability to work together with other performance indices, i.e. the likelihood associated with one state. The possible values according to system states can be derived using inductive methods. If one wants to calculate the probability to occur a particular event in the system, then must be applied the deductive methods. In the particular case of the human reliability analysis, as part of probabilistic safely analysis, the international regulatory commission have developed the specific guides and procedures to perform such assessment (International Atomic Energy Agency: Procedures for conducting probabilistic safety assessment of nuclear power plants, 1992). The paper presents the modality to perform human reliability quantification using Petri nets approach. These are an efficient mode to assess reliability systems because of their specific features. The examples showed in the paper are from human reliability documentation without a detailed human factor analysis (qualitative). We present human action modelling using event trees and Petri nets approach. The obtained results by these two kinds of methods are in good concordance.