A Hybrid MCDA Methodology to Evaluate Ferry Fleet Assignment to Routes in the Greek Islands

It is acknowledged by numerous researchers that island residents experience inequality with respect to their accessibility in comparison to the rest of Greek residents, as they are dependent on the frequency, quality of service, and capacity that ferry operators provide. Consequently, to the fact that the ferry business is a free market (due to: (i) no barriers to entry; and (ii) minimum state interventionism in routings), current ferry services operate as “selfish routings” and do not consider the transport system as a whole. This may lead to social welfare loss. This work proposes a hybrid methodology using two MCDA methods (AHP and PROMETHEE) to evaluate whether total ferry fleet assignment to routes is optimal in a holistic manner, from a transport system perspective. Eight “key” routes are considered. For all routes, 6 criteria are introduced, on the basis of which different ferries are evaluated. These criteria are passenger capacity (number), lane meters (number), cabin berths (number), speed (knots), maneuvering ability of ship (index), and comfort (index). Weights of criteria for each route are calculated (8 times, one for each route) through AHP approach, by expert’s input from different categories of stakeholders. Results indicate that the current ferry system can become more efficient by permutation (i.e. exchanging) of currently operating ferries between different routes. The proposed fleet assignment: (i) increases the quality of service for several routes; (ii) increases the accessibility of islands (as it contributes towards better capacity management and leads to less skipped port calls due to bad weather); and (iii) increases efficiency due to greater load factors.