A novel navigational risk analysis method using interval type-2 fuzzy sets

Navigational risk is critical to the shipping industry, particularly to the inland water due to its sensitive environment. To this end, this paper proposes a novel method for navigational risk analysis, incorporating Analytic Hierarchy Process (AHP), interval type-2 fuzzy sets (IT2FSs), and a similarity measure. In light of literature review, a hierarchical model for navigational risk analysis is developed including three levels: objective level, criteria level, and factor level. Then, weights of criteria and associated factors are obtained using AHP, and factors are evaluated by experts using IT2FSs. Then, results of the degree of similarity between aggregated experts' evaluation and 7-member IT2FSs representing 7 grades of risk are obtained and used to determine the degree of navigational risk of the objective level. The application of the proposed method is illustrated by assessing navigational risk of 5 vessels cruised in the Yangtze River. The proposed method provides room for more flexibility in modeling and handling subjective uncertainties in navigational risk analysis. Also, the proposed method identifies navigational risk of multiple vessels, which is useful in enhancing situation awareness of safety.