Use of fuzzy logic approaches to safety assessment in maritime engineering applications

Abstract

Safety assessment based on conventional methods such as probability risk assessment (PRA) may not be well suited for dealing with innovative systems having a high level of uncertainty, particularly in the feasibility and concept design stages of a maritime engineering system. By contrast, safety models using fuzzy logic approaches employing fuzzy IF-THEN rules can model the qualitative aspects of human knowledge and reasoning processes without employing precise quantitative analyses. Fuzzy-logic-based approaches may be more appropriately used to carry out risk analysis in the initial design stages of large maritime engineering systems. This provides a tool for working directly with the linguistic terms commonly used in carrying out safety assessment. This paper focuses on the development and representation of linguistic variables to model risk levels subjectively. These variables are then quantified using fuzzy set theory. In this paper, the development of two safety evaluation frameworks using fuzzy logic approaches for maritime engineering safety-based decision support in the concept design stage are presented. An example is used to illustrate and compare the proposed approaches. Future risk analysis in maritime engineering applications may take full advantages of fuzzy logic approaches to complement existing ones.