Time sequence ordering extensions to the Entity-Relationship model and their application to the automated manufacturing process

摘要

New extensions to the entity-relationship (E-R) model have been developed to represent time sequencing and ordering aspects of information flow, and to represent the integration of control (programming) information into a database. The model constructs specify an implementation ordering of records in a relational database table. Time sequencing refers to an implementation of process information flow as a result of this ordering. The modeling constructs are needed to more completely model process recipe information flow in a typical automated manufacturing facility. The development of these E-R extensions is pursued using a data model for the factory of the future as a motivation and development vehicle. The extensions are defined formally and possible variations of the constructs are given. Further, the incorporation of the constructs into the existing E-R model semantics and the transformation of these extensions to ordering properties and integrity constraints on a corresponding database implementation is discussed.