A design methodology for databases with uncertain data

Many real world systems and applications require information management components that provide support for managing imprecise data. There have thus been several proposals for extending relational database systems in order to represent as well as query such imprecise data. Little work, however, has been done in modeling uncertainty at the conceptual schema level and in developing design methodologies for developing fuzzy relational databases (FRDBs). To fill this gap, a design methodology for FRDBs is proposed. This methodology contains extensions for representing the imprecision of data in the entity-relationship (ER) data model, and a set of steps for the derivation of a FRDB from this extended ER model. As a case study, this methodology has been applied to the design of a control database for semiconductor manufacturing