Safety assessment of control system based on fuzzy comprehensive evaluation

Petrochemical industry, where large amounts of dangerous chemical substances are stored and handled, maybe subjected to hazards. As control system is widely used in petrochemical industry, safety assessment is becoming increasingly important for control system in order to minimize catastrophic events while improving safety, reliability and availability. But a number of uncertainties connected with information shortages may lead to overlooking of safety assessment of control system. Fuzzy-set theory, deals with uncertainty, is an efficient tool to solve this problem. This paper provides a new safety assessment to get the general control system safety score by using an improved fuzzy comprehensive evaluation. This improved fuzzy comprehensive evaluation based on fuzzy-set theory use multi-level fuzzy comprehensive evaluation to manage weight vector and fuzzy membership vector which are obtained from analytic hierarchy process and safety checklist respectively. After improved fuzzy comprehensive evaluation process, a proposed methodology is built upon fuzzy mathematics theory to obtain control system safety score. Finally, a case from a field control station is successfully presented to illustrate the proposed approach.