Fuzzy AHP-Based Design Performance Index for Evaluation of Ferries

Within waterborne public transportation (WPT), one often observes a mismatch between the operational requirements and ferry characteristics. A method to holistically evaluate ferries with respect to local requirements could lead to tailored procurement and targeted refurbishment of existing fleet. In this study, we develop a structure for operational requirements and use it as a basis for a ferry evaluation methodology. The requirements' structure follows a three-level hierarchy starting from broad vessel design to mandatory requirements to performance requirements. The performance requirements are based on the three pillars of sustainability, aided by commuter surveys carried out in Stockholm ferries, interviews with public transport providers (PTP) and previous literature. The evaluation of the ferry is performed using analytic hierarchic process (AHP) to convert the PTP's subjective preferences and ferry performance into a single dimensionless index. Rules for quantification of performance metrics including social performance are proposed. The uncertainties associated with AHP are addressed by employing fuzzy AHP based on extent analysis and fuzzy AHP in combination with particle swarm optimization. Two applications including performance assessment of existing ferries and assembly of a modular ferry are discussed. The method can lead to objective decision making in ferry evaluation, potentially leading to a more efficient WPT.