A fuzzy multi-attribute HAZOP technique (FMA-HAZOP): Application to gas wellhead facilities

Hazard and Operability analysis (HAZOP) is a popular technique for hazard identification and risk ranking in hazardous facilities. Conventional HAZOP, however, has some drawbacks: (i) it considers a limited number of risk factors, i.e., only the frequency and the severity of hazards; (ii) it assumes equal weights for the risk factors, thus ranking low-probability high-consequence hazards equally important as high-probability low-consequence hazards; and (iii) it uses crisp and precise data which is rarely available or highly uncertain, especially in the case of complex oil and gas facilities. The present study is an attempt to alleviate the foregoing drawbacks of conventional HAZOP via a Fuzzy Multi-Attribute HAZOP technique (FMA-HAZOP). To do this, Analytic Hierarchy Process (AHP) and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) are used, both in a fuzzy environment, to determine the weight of risk factors and to prioritize the hazards. The application of the FMA-HAZOP on a gas wellhead facility shows that FMA-HAZOP presents a more transparent and more detailed information about the rank of hazards compared to conventional HAZOP.