Proceedings of the

The 33rd European Safety and Reliability Conference (ESREL 2023)
3 – 8 September 2023, Southampton, UK

Process Hazard Analysis: Proposing a Structured Procedure based on Multilevel Flow Modelling

Ruixue Lia, Jing Wub, Xinxin Zhangc and Ole Ravnd

Department of Electrical and Photonics Engineering, Technical University of Denmark, Denmark.


Process hazard analysis is significant in improving process safety in complex systems. Hazard and operability study (HAZOP) is one of the event-based methods of displaying hazards in the process industry, which can identify a wide range of hazards throughout the process life. However, HAZOP would repeat work on the same failure and lack a global view, as well as the result is not highly readable and reusable. Therefore, a hazard analysis procedure based on Multilevel Flow Modeling (MFM) is proposed. The procedure divides the system into sub-objectives and flow-based structures, subsequently analyzing and modeling hazard knowledge in terms of the objects and agents that realize the function. By comparing with a HAZOP report of the Minox process in a water injection system, it is demonstrated that MFM-based hazard analysis shows the potential for a more systematic and comprehensive representation of process hazards to improve process safety management.

Keywords: Process Hazard Analysis (PHA), HAZOP, Multilevel flow modelling, Process hazard procedure, Functional modeling, Process safety.

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