Iran Occupational Health

  Background and aim: Today, it was revealed that Socio-technical systems did not have a bimodal nature and interactions in these systems are complex and non-linear. Consequently, since risks can be emerged as non-linear combinations of performance variability, so traditional methods of risk assessment are not able to capture these combinations. The present paper is aimed at identifying the emergent risks by means of the Functional Resonance Analysis Method in a process unit of an oil refinery.

  Method: To identify the emergent risks in the functions, first the essential system functions including twenty five functions of human and four functions of organization were identified in an oil process unit. Then, potential variability (emergent risks) was characterized among the mentioned functions using a technical checklist. After then, resonance phenomenon was evaluated among the functions with regard to possible dependencies/couplings among functions and their effect on each other. Finally, mechanisms and barriers such as physical, symbolic, functional, etc., which were utilized to damp the variability, were identified.

  Results: The results showed that the possibility of the high variability in fourteen human functions is likely, but the analysis of different scenarios revealed that five human functions contain the emergent risks, and should be controlled. These risks go beyond component failures and malfunctions.

  Conclusion: with regard to the results of this research and the conducted researches in the world, this model is so applicable to understand dynamics and nonlinearity of functional resonance in socio-technical systems in order to avoid accidents.