A systematic formulation for HAZOP analysis based on structural model

The combination of an automatic HAZOP analysis with a structural model was introduced to obtain a systematic procedure for hazard and mal‐operations identification. There are three stages of the proposed procedure. The first stage was used to analyze the conventional hazard and mal‐operations for each process unit, whereas the second stage extended the analysis to adjacent units. The interaction style was used to identify the cause–consequence relationships between upstream and downstream unit with the concepts of the non‐local path and the dummy parameters. Therefore, a generic HAZOP library will be additional modified. The third stage created the templates for hazard and mal‐operations identification for operating arbitrary units. This proposed HAZOP analysis was verified with conventional HAZOP of the defatted soy flour pilot plant with three scenarios. The analysis scheme fulfilled the library of the case study and discovered 18 new consequences for the first scenario, 10 new consequences for the second scenario. For the third scenario, the analysis specified on an arbitrary flash drum by applying three guide‐words (more, less and no) and found 46 causes and 83 consequences. The proposed methodology, therefore, can simplify and reveal the guidance for hazards and mal‐operations identification.