Using invariants of an extended conceptual model to generate reusable consistency control

A methodology is presented that allows to specify and implement an important portion of consistency control in information systems in integrated and reusable form. An extension of the structured entity relationship model is proposed that captures not only all relevant variants of database abstractions, but also derivation rules. Invariant properties of this extended conceptual model are identified and formally specified. From that formal specification, general rejection and propagation rules are derived which can be used to generate database triggers. Being an integral component of the procedurally extended database, the generated triggers are reused by every application within the information system. The methodology was integrated into commercial CASE environments and applied to develop a production management information system for a large mechanical engineering company.