Fuzzy systems approach versus possibility theory approach for representing customers' stated preferences on freight transport services

Everyday companies’ logistic managers are involved in choice processes addressed to the identification of the “best” solutions as regards freight transportation in supply and distribution; choices are achieved evaluating alternative services according to companies’ needs. Otherwise transportation services providers (e.g. shipping agents), in order to better answer to the companies’ needs, offer a wide range of transportation services. The first objective of the research described in this paper is to find out a ranking of preference on transportation hypothetical alternatives proposed, with the necessity to maintain, in the analysis phase, the uncertainty associated with evaluations of the semantic type expressed by interviewees. In order to achieve this objective two different approaches were adopted: the first based on fuzzy sets and possibility theory and the second based on fuzzy systems methodologies. The second objective is to evaluate the capabilities of the two approaches to predict the behaviour of decision makers in the choice of freight transportation services, making a comparative analysis with the so-called ROC (Receiver Operating Characteristic) curve analysis method.