F-Cube Factory: a Fuzzy OLAP System for Supporting Imprecision

The special needs of the OLAP technology was the main cause of the use of a multidimensional view of the data. As a result of the use of this technology in new fields of knowledge (e. g. medical data) and the integration of data from heterogeneous sources, it has become necessary for multidimensional models to supports new needs. To model complex or nor well defined domains or to integrate data from semi/non-structured sources (e.g. Internet) or with incompatibilities in their schemata is complicated using crisp multidimensional models. In these situations we need a model able to manage imprecision in the structures and data as a result of the modelling and/or integration. In this paper we present an OLAP system based on a fuzzy multidimensional model that uses fuzzy logic. The use of fuzzy structures (hierarchies and facts) and the definition of the normal OLAP operations (roll-up, drill-down, dice, slice and pivot) enable the model to manage the imprecision of these situations, hiding at the same time the complexity to the user by means of user views.