1 AN ALGEBRAIC APPROACH TO CONSISTENCY CHECKING BETWEEN CLASS DIAGRAMS

There are several diagram methods for data modeling like a class diagram. It is very hard to describe a big data model of a large enterprise system into one diagram. A large set of partial data models are used during designing an information system for a large enterprise. The skill of modelers makes fluctuation and discrepancy among data models. It is necessary how to keep consistency among data models. There are two kinds of inconsistency among data models described in class diagrams. One is inconsistency between two data models like differences between attributes, data types, or multiplicities of same name classes. The other is inconsistency depending on order of divides and mergers for data models. We present syntax and semantics of a class diagram describing a data model for foundation for class diagram algebra. Then we introduce algebraic structure for syntactical and semantical merger operations on class diagrams and the consolidation condition. Satisfying the consolidation condition keeps consistency of class diagrams syntactically and semantically. We also show associative law and commutative law of the syntactical and semantical merger operations for the class diagram algebra that keeps avoiding inconsistency depending on order of divide and merging