Qualitative Risk Analysis

Some of the techniques applied to assist in the identification of hazards include – HAZOP, HAZID, SIL studies, constructability reviews etc. Hazard & Operability (‘HAZOP’) study is the industry-standard technique used to identify and address safety, environmental and operability concerns when reviewing process engineering designs. HAZOP study is an important contributor to the Hazard Management Process. Hazard Identification (HAZID) is a similar technique used when there is more emphasis on external hazards rather than just process hazards. A constructability review follows a similar pattern to a HAZID, but with focus on construction, installation and commissioning of an equipment, skid or plant unit. Safety Integrity Level (SIL) Classification is the process of determining the SIL requirement. It entails evaluating the risk that would be obtained in the absence of the Instrumented Protective Function (IPF) (the unmitigated risk) and comparing it with the applicable criteria for tolerability of risk (TOR). Any shortfall represents the risk reduction that is required of the IPF.